January

Garnet has been the birthstone for January since the 15th century, at least. With a Mohs hardness of 6.5 to 7.5, it can be faceted into beautiful gemstones that wear well in jewelry. Since the term “garnet” actually refers to a group of nesosilicate gems, those born in this month can choose from a rainbow of colors.

The most common members are red almandine, an iron-aluminum silicate; red pyrope, a magnesium aluminum silicate; orange-yellow spessartine, a manganese aluminum silicate; the yellow or green varieties of andradite, a calcium-iron silicate; predominately green grossular, a calcium-aluminum silicate; and rare, bright-green uvarovite, a calcium chromium silicate.

February

From the 15th century to the present, amethyst has been the preferred birthstone for February. Amethyst belongs to a mineral family that can compete with garnet for diversity of color: quartz.

Pure quartz is colorless, as exemplified by Herkimer diamonds. The causes of amethyst’s shades of pale violet to rich purple are radiation and the inclusion of iron impurities and trace elements.

As a rule, amethyst crystals are short and stubby, and occur in large numbers, often filling a large vug a hollow petrified tree section, or lining the inside of a geode. Fine crystals that are large enough to produce a faceted gem of over 20 carats are rare.

March

The current choice of a birthstone for March is aquamarine. Aquamarine is a variety of beryl (Mohs 7.5-8). Its name was derived from the fact that the beautiful, transparent, blue-green coloration of the gem resembles that of seawater. It can be found in translucent to transparent crystals that form in the hexagonal system. The six-sided crystals are often striated lengthwise.

Aquamarine develops in metamorphic rocks and, more often, in pegmatites.

April

Before 1900, a person with an April birthday had two choices of birthstone: diamond or sapphire. During the 20th century, however, diamonds became the preferred stone.

Diamond, a mineral consisting of pure carbon, heads the list of all gemstones for its beauty and hardness. A 10 on the Mohs Scale of Hardness, it is resistant to scratching and is an ideal gem to set in rings. Its hardness results from the arrangement of its atoms in cubes.

All diamonds have slightly rounded faces, and they’re so smooth they feel greasy to the touch. They can be colorless and water clear to blue, pink, yellow, brown, green or black, and transparent or translucent. They shine with an adamantine luster when held to the light.

May

There were two choices for May birthstones for several hundred years: emerald and agate. The popularity of agate seems to have waned at the turn of the 20th century, so emerald is now the favorite. It’s the green member of the beryl family of gemstones. The color varies from bright green to pale green and, sometimes, darker shades of blue-green.

Fine emeralds have a velvety surface appearance and, in the better stones, an even distribution of color. One bad trait of emeralds is a tendency to have inclusions. It’s rare to find an emerald without some slight imperfection. This in no way deters from the beauty of this gemstone, though. It can also be one way of determining whether an emerald is a simulated gem or the real thing, as manmade stones have no imperfections.

June

The contemporary choices for June are pearl, moonstone and alexandrite. Of course, a pearl is the organic product of marine bivalves and not a mineral.

Moonstone is a variety of feldspar that shows adularescence, or schiller, an optical effect that produces a milky luster with a bluish tinge that appears to move across the stone when it is tilted. The phenomenon is named after the feldspar variety adularia.

Alexandrite is a color-change variety of chrysoberyl (beryllium aluminum oxide). This is a very rare and expensive gemstone. It has a hardness of 8.5, and its crystals are either tabular or prismatic. The distinction between alexandrite and chrysoberyl is simply color. A strange characteristic of alexandrite is that it is red, purple or violet when held under artificial light, but in daylight, it looks green.

July

Ruby is the standard birthstone for the month of July. It is a corundum (aluminum oxide) gem that gets its color from the presence of chromium in its structure. An exceptionally hard mineral, corundum illustrates a hardness of nine on the Mohs scale. “Pigeon-blood” red is the preferred color for rubies, though they also occur in lighter shades, including pink. All other colors of corundum are called sapphires.

Ruby exhibits all the desirable properties of a jewelry stone: beauty, durability, optical properties, and rarity. Some rubies display a star or asterism when fashioned into a cabochon. This effect is caused by the reflection of light from numerous inclusions of minute, needle-like crystals of rutile. Corundum crystallizes in the hexagonal system with a tabular-barrel-shaped habit.

August

Current birthstones for August are peridot, the gem-quality form of olivine and spinel. Olivine makes up a large portion of the earth’s mantle. Rocks containing olivine have been brought to the surface by volcanic action and actually blown out in the form of volcanic bombs. Masses of olivine have been found in meteorites, and the Apollo astronauts brought basaltic rocks back from the moon that contained olivine.

A popular jewelry stone, peridot has a hardness of 6.5-7 and can be transparent or translucent, with a vitreous luster. Its color shades from deep green to apple green, yellow-green or olive. It’s most often found in granular nodules, forming short, prismatic crystals in the orthorhombic system.

Spinel is the gem-quality member of the larger spinel group. Its hardness (Mohs 7.5-8.0) makes it ideal for jewelry use. Its spectrum of colors includes red, pink, purple, blue and lavender. In times past, red spinel was often mistaken for ruby. A notable example is the Black Prince’s Ruby, set in the royal crown of England.

September

The birthstone for September is sapphire. This term refers to any corundum (aluminum oxide) gem that has any color other than red (ruby). Sapphires may be colorless, blue, green, yellow, orange, brown, pink, purple, gray, black, or multicolor. At Mohs 9, its hardness is second only to that of a diamond.

Heat treatment is sometimes used to give natural blue sapphires a deeper, more pleasing color. Natural star sapphires, which display the optical phenomenon of asterism, are very rare.

October

Two options for October are opal and tourmaline. Opal is a magnificent gemstone with a play of color or “fire” in all colors of the spectrum. Spaces between the tiny spherules of silica that make up the gem diffract light into its spectral colors. Red, yellow, green and blue, in strong to pastel shades, flash from the stone when it is tilted.

Opal occurs in common and precious types. Common opal does not display any reflective fire. It may have a honey-yellow, brown, gray or colorless body color that is milky and opaque. Opal (Mohs 5-6) is not a very hard gemstone.

Tourmaline, a silicate of boron, has a complicated chemical composition, in which a number of elements, including calcium, iron, sodium and aluminum, may combine. It has a Mohs hardness of 7-7.5.

It belongs to the trigonal crystal system and its habit is hemimorphic (a crystal having two ends of an axes unlike in its planes).

Because of the coloration of the individual stones, tourmaline has several names, including schorl (black), rubellite (red), indicolite (blue), and dravite (brown). Tricolor crystals are common. The popular watermelon variety has an outer layer of green around a red core.

November

The current birthstones for November are topaz and citrine. People tend to think of topaz, a silicate mineral with aluminum and fluorine, as a yellow stone, but heat-treating and color-enhancing adaptations have made blue the predominant color on the market. It is an allochromatic mineral, which means its color is caused by internal defects in the crystal and has a Mohs hardness of eight.

Citrine is the golden member of the quartz family (silicon dioxide). Though quartz in its many forms is one of the most abundant minerals on earth, fine, gem-grade crystals are not that common. Citrine is affordable and, when faceted, rivals more expensive gemstones in beauty.

December

There are three birthstones for December: turquoise, blue zircon and tanzanite. Turquoise (hydrated copper aluminum phosphate) is an opaque, blue-to-green, massive gem material. It has a relatively low hardness of Mohs 5-6, so care must be taken with turquoise jewelry.

The rarest and most valuable variety is robin’s-egg blue with black “spiderweb” veins of limonite. Fake turquoise, consisting of dyed howlite or magnesite, is common. Buyer beware.

Zircon (zirconium silicate) can be blue, black, red, brown, green, yellow, smoky, or water-clear. It has an adamantine luster much like that of a diamond, and it is often misidentified as such.

Tanzanite, the blue/purple variety of zoisite (basic calcium aluminum silicate), is a recently introduced alternative for December. Tanzanite crystals in shades of yellow to brown, green, pink, gray or blue are often heat-treated to produce a gemstone that is a beautiful and permanent blue.

This story about what are birthstones by month previously appeared in Rock & Gem magazine. Click here to subscribe! Story by Kenneth H. Rohn.

The post What are the Birthstones by Month? first appeared on Rock & Gem Magazine.

Tourmaline Colors

One reason for tourmaline’s popularity is its wide array of colors – over 100! The mineral colors are caused by traces of different chemicals. For example, iron produces blue (indicolite) and green colors and manganese produces pink and red colors. Sometimes tourmaline colors are enhanced by heat treatment.

There are five major tourmaline species.

1. Dravite

2. Elbaite – Named after Elba, Italy. Most gem varieties occur in this species.

• Rubellite – Pink
• Paraíba (named after Paraíba, Brazil)
• Watermelon Tourmaline – (red center and green rind)

3. Liddicoatite

4. Schorl – Black (colored by iron)

5. Uvite

Tourmaline may form beautiful, elongated crystal clusters that are highly sought after by collectors. It is one of the most prized minerals and stunning specimens can be among the most aesthetic examples in the mineral kingdom.

Tourmaline Facts

Tourmaline has a Mohs hardness of 7.5 and crystallizes in the trigonal system. Most crystals are striated, elongated and prismatic. Vitreous luster and conchoidal fracture are also characteristic. Chatoyancy (cat’s eye effect) is found in some tourmalines.

Besides its use in jewelry, tourmaline becomes electrically charged when it’s heated. Piezoelectric properties can make tourmaline useful in the manufacture of various industrial gauges.

Confident Tourmaline

In the metaphysical realm, tourmaline is thought to give confidence, relieve nervousness, promote self-assurance, increase physical energy, enhance the immune system, help negate negative thoughts and relieve tension.

Tourmaline is the gemstone for the eighth anniversary and a birthstone for October.

Where to Find

Afghanistan; Australia; Brazil; China; Congo; India; Italy; Kenya; Madagascar; Mexico; Morocco; Mozambique; Myanmar; Namibia; Nepal; Nigeria; Pakistan; Russia; South Africa; Sri Lanka; Sweden; Tanzania; Thailand; United States of America; Urals; Zambia

This story about tourmaline previously appeared in Rock & Gem magazine. Click here to subscribe! Story by Richard Gross and Pam Freeman.

The post Tourmaline: Properties and ID first appeared on Rock & Gem Magazine.

San Diego Natural History Museum

At the famous Balboa Park in San Diego, just south of the San Diego Mineral and Gem Society & Museum, is the San Diego Natural History Museum — or the “Nat” as the locals call it. The San Diego Natural History Museum is one of the most significant natural history museums in the country.

The San Diego Society of Natural History dates to 1874. In 1917, the San Diego Mineral and Gem Society purchased a vacant building from the 1915 Panama-California Exposition. Later, a new building was commissioned to architect William Templeton Johnson to fit the museum’s expanding needs. The new museum opened in 1933 serving visitors for decades, before undergoing a significant renovation. In 2001, after a nine-year and $38 million capital campaign, the museum reopened its doors. The major renovation added 90,000 square feet, more than doubling the museum’s size.

A Rich Mining History

San Diego County’s pegmatite mines are famous for their pink elbaite tourmalines and green and blue tourmalines. The Pala Gem district, near the town of Pala, is also renowned for its other pegmatite minerals – quartz, feldspar, garnet, lepidolite, morganite, aquamarine, and kunzite. Since the second half of the 19th century, the mines were worked with lithium-bearing lepidolite being the primary target. Then, in 1898, pink tourmaline was found at the Himalaya Mine, and later at the Stewart Mine.

Mining Pink Tourmaline

Pink tourmaline’s beauty attracted a far-away royal who became a patron, the Empress Dowager Tzu-Hsi (pronounced “Tsoo Shee”), or Cixi of China. The craze for pink tourmaline took place at the turn of the 20th century, and Tiffany’s & Co. facilitated the export. Between 1902 and the Dowager’s death in 1911, 120 tons of tourmaline were mind, with the majority sent to China. The beginning of the Chinese revolution and the abdication of her son, Emperor Puyi, in 1912, and the onset of World War I caused the mines to go dormant.

In 1969 the Pala Stewart mine hit a new tourmaline find and the Tourmaline Queen mine produced the most famous blue-cap pink tourmaline specimens, some with peach-colored morganite attached.

Finding Kunzite

Another famous gem discovered within the same pegmatite mines was kunzite. This mineral is the pale purple/pink variety of spodumene. When the early specimens were found, they were sent to George F. Kunz, a gemologist at Tiffany’s, who identified the mineral and named it after himself.

Pink Tourmaline @ the Oceanview Gem Mine

Today beautiful tourmaline and kunzite are mined at the Oceanview Gem Mine. Besides the daily underground mine operations and pursuit of great minerals, the mine is open to the public for fee-digging.

The mine is located east of Pala township, in San Diego County, and has been owned, since 2000, by Jeff Swanger. The screening process involves Swanger and his team bringing out gem-bearing material blasted from inside the mine and depositing it on a pile in the center of a cleared-out area. There are tables, tubs with water, and screens, where visitors can screen for gems, mostly kunzite and quartz, and some tourmaline specimens. Fee digging starts at 11 a.m. and ends at 3 p.m., on Thursday, Saturday and Sunday. Reservations are required to participate in fee digging.

Depending on your expertise and luck, you may come away with some excellent specimens if you visit.

Himalaya Tourmaline Mine

Another spot in the area, also open for fee-digging is the Himalaya tourmaline mine, owned by High Desert Gems & Minerals. The mine is located near Santa Ysabel at Lake Henshaw. It is open Thursday through Sunday, and again, you keep all you find.

Additionally, the museum’s fossil collection includes the Cerutti Mastodon — a selection of 130,000-year-old preserved mastodon bones, molars, and tusks. Another exciting part of the collection is the Fossil Mysteries, which showcases 75 million years of southern California and Baja California fossil history.

This story about pink tourmaline previously appeared in Rock & Gem magazine. Click here to subscribe. Story by Helen Serras-Herman.

The post Pink Tourmaline & Fossils in San Diego first appeared on Rock & Gem Magazine.

Gemstones of the Bible – Sacred Breastplate

The Bible’s most celebrated – and debated – reference to gemstones regards the sacred breastplate of the high priest of the Israelites, also known as “Aaron’s breastplate” and the “breastplate of judgment.” Described in detail in the Old Testament’s Book of Exodus, this golden breastplate was set with 12 different gemstones arranged in four rows of three gemstones each. Each gemstone was identified in ancient Hebrew, the original language of the Old Testament.

But the text of the original Hebrew Bible and the meanings of many ancient Hebrew words are now largely lost. Our knowledge of the Old Testament as presented in the Bible’s many English versions is based on 2,500 years of scholarly interpretation of Greek, Aramaic, and Latin translations

Gemstones of the Bible – Debating Identities

Not surprisingly, the identities of the breastplate gemstones have become confused. Modern English versions of the Bible collectively offer more than 40 different identities for the 12 breastplate gemstones. Most are modern names of gemstones, minerals, and mineral varieties, along with some archaic English names and several untranslated Greek and Latin names.

Adding to the confusion, modern artistic depictions of the breastplate often disregard the probable color and transparency of its gemstones. Many depict the gemstones as faceted, transparent gems, even though faceting as we know it today was not developed until about 1400 C.E. Prior to the first century B.C.E., most gemstones were opaque or translucent and were fashioned as cabochons.

For centuries, historians, theologians, and scholars have debated the identities of the breastplate gemstones and agree only on the general historical background of the breastplate itself. According to biblical scholars, the Old Testament was written over a period of 1,000 years, roughly from 1400 to 400 B.C.E. The breastplate was created about 1450 B.C.E. during the time of Moses. The Book of Exodus, which contains the breastplate description, is based almost entirely on oral tradition and was written in stages between 600 and 400 B.C.E.

Gemstones of the Bible – Tricky Translations

Most interpretations and translations of the names of the breastplate gemstones were provided by scholars with little, if any, geological, gemological, mineralogical, or sometimes even historical, awareness. Their translations are based largely on tradition, limited gemstone knowledge, personal whim, or simple phonetics – sapphieros must mean “sapphire,” and topazos must means “topaz.”

But Dr. James A. Harrell, Professor Emeritus of Geology at the University of Toledo, has taken a different approach to identify breastplate gemstones. A specialist in the archaeological geology of Egypt and the Middle East, Harrell presents his ideas in a paper published in the Bulletin for Biblical Research and titled “Old Testament Gemstones: A Philological, Geological, and Archaeological Assessment of the Septuagint.”

The Septuagint is a third through first-century B.C.E. Greek translation of the original Hebrew Bible. The name “Septuagint” stems from the Latin septu gint, meaning “seventy” and refers to the number of Jewish scholars who worked on the translation. As a first-generation translation, the Septuagint is the most direct linguistic link to the identities of the breastplate gemstones.

Gemstones of the Bible – Breastplate Order

In his research, Harrell considered all Septuagint passages that mention gemstones and not just those related to the breastplate. He also consulted numerous other contemporaneous ancient texts that describe gemstones that are likely the same as those in the breastplate.

Historically, Harrell considered the gemstones that were known to be in use in the greater biblical region (southwestern Asia, Egypt, and the eastern Mediterranean) during the first millennium B.C.E. He also applied geological criteria to gemstone identification and drew upon his own field research and personal examination of ancient gemstones in museum collections.

As described in Exodus, the order of the breastplate gemstones progresses from right to left, as does ancient Hebrew writing. The first stone in each row, therefore, appears at the right and the third stone in each row at the left. In the following discussion, the stones are identified by the transliteration of their Septuagint Greek names that have so confused translators.

Sardion

Sardion is the first stone in row one of the breastplate. It has been translated as “carnelian,” “sard,” “sardonyx,” and “red jasper.” Archaeological recoveries indicate that carnelian and sard, both translucent forms of microcrystalline quartz, were the most common gemstones throughout the biblical region during the first millennium B.C.E. Carnelian is reddish; sard is brownish. Sardonyx is a brown-and-white-banded type of sard. Red jasper, an opaque form of microcrystalline quartz, also served as a gemstone, but not nearly to the extent of carnelian.

In his Naturalis Historia, the Roman scholar Pliny the Elder (Gaius Plinius Secundus, 23-79 C.E.) describes sardion as a widely used, “fiery, red gemstone.” As a gemstone for the breastplate, Harrell concludes that bright-red carnelian would certainly have been chosen over sard, sardonyx, or red jasper.

Topazos

Topazos is the second stone in row one of the breastplate. Topazos has been translated as “topaz,” “chrysolite,” “emerald,” and “peridot.”

Its earliest reference, written in the second century B.C.E., describes “a delightful, transparent stone similar to glass and with a wonderful golden appearance.” Another calls it “topazion Ethiopias,” meaning “topazos from Ethiopia.” During the biblical period, “Ethiopia” referred to Egypt’s Eastern Desert and nearby Red Sea islands.

Pliny writes that this stone came from the Red Sea island of Topazum (now Zabargad Island). He calls it the largest of the precious gemstones and the only one that is affected by an iron file – a description that indicates topazos is peridot, the gem variety of the olivine-group mineral forsterite (magnesium silicate). At Mohs 6.5, peridot is just soft enough to be scratched with an iron file, unlike the harder emerald and quartz gemstones. And the basalt formations of Zabargad Island, a classic peridot locality, have yielded very large peridot crystals.

Topaz, or basic aluminum fluorosilicate, is much harder than peridot and does not occur in basalt. Topaz was given its modern name in the 18th century when it was confused with the ancient topazos. Harrell is confident that the breastplate’s topazos is definitely peridot.

Smaragdos

Smaragdos is the third stone in row one of the breastplate. Smaragdos has been translated as “beryl,” “carbuncle,” “emerald,” “malachite,” and “turquoise.” In his On Stones, the Greek scholar Theophrastus (ca. 371 – ca. 287 B.C.E.) writes that smaragdos refers to a group of bluish and greenish stones and that it is “good for the eyes,” implying a cool, soothing color. He also mentions that blocks of smaragdos large enough to fashion into obelisks were common.

Emerald was not readily available until mines in Egypt’s Eastern Desert opened in the late first century B.C.E. At that time, smaragdos was also referred to as emerald, probably because of its similar green color. But the size of the smaragdos that Theophrastus describes certainly does not indicate emerald.

Some early descriptions of smaragdos would fit malachite. During the first millennium B.C.E., malachite was mined as the primary ore of copper on Cyprus and the Sinai Peninsula, and in Israel’s Timna Valley. Malachite was associated with such colorful, oxidized copper minerals as turquoise, azurite, and chrysocolla, which sometimes occurred in large, intermixed blocks.

Anthrax

Anthrax is the first stone in row two of the breastplate. Anthrax has been translated as “carbuncle,” “emerald,” “ruby,” “turquoise,” and “red garnet.” The Greek word anthrax refers both to hot embers and to a gemstone with a similar, glowing red color. Theophrastus describes it as “very rare and small, and carved into signets,” and compares its color when held against the sun to that of a glowing, red coal. He notes anthrax being “angular and containing hexagons.” Garnet group minerals, which crystallize in the cubic system, often occur as spheroids with hexagonal faces.

Pliny, who refers to anthrax as carbunculus, notes its “exceptional brilliance.” The substantial density of garnet-group minerals produces a high index of refraction and thus greater “brilliance” than many other red gemstones. Pliny also observes an amethyst-violet tone in the basic red color of anthrax. The almandine-pyrope garnet series, which has purplish-red colors, were the garnets mainly used in antiquity. Although garnet was occasionally found in the biblical region, most came from India after the third century B.C.E. Harrell concludes that the breastplate’s anthrax is red garnet, most likely a member of the almandine-pyrope garnet series.

Sappheiros

Sappheirosis the second stone in row two of the breastplate.

Sappheiros, the origin of our modern word “sapphire,” has been almost universally translated in the Bible as “sapphire.” Yet sappheiros is actually lapis lazuli, a prized gemstone and a major trading commodity throughout the biblical period.

Lapis lazuli is a metamorphic rock consisting of lazurite, calcite, pyrite, and other minerals. Lazurite, a basic sodium calcium aluminum sulfate chlorosilicate, is the primary mineral in lapis lazuli and the cause of its striking blue color. In top-quality lapis lazuli, pyrite appears as glittering, disseminated specks. Many ancient writers have compared the dark-blue color and glittering pyrite specks of sappheiros to a star-filled night sky.

Since 4000 B.C.E., the Sar-e-Sang mines in northeastern Afghanistan have produced the world’s finest lapis. The corundum gemstone we now know as sapphire was not available in the first millennium B.C.E. Had it been available, its extreme hardness would have made it very difficult to work.

There is no doubt that the breastplate’s sappheiros is not sapphire, but lapis lazuli.

Iaspis

Iaspis is the third stone in row two of the breastplate.

The Bible’s long list of iaspis translations include “beryl,” “diamond,” “rock crystal,” “emerald,” “jasper,” “onyx,” “moonstone,” “chrysoprase,” and “amazonite.” Theophrastus writes that iaspis was carved into seals, and groups it with smaragdos, implying that it has a bluish or greenish color.

Pliny describes it as “a highly prized stone,” translucent and with blue and green varieties. Although these descriptions are general, iaspis could be greenish microcrystalline quartz, perhaps a color variation of jasper. Iaspis is also the origin of the modern word “jasper.”

But another possibility is amazonite, the green-to-blue variety of microcline feldspar, which was mined in Egypt during the first millennium B.C.E. and saw limited use as a gemstone. However, Harrell believes that iaspis is more likely a greenish microcrystalline quartz, perhaps a form similar to chrysoprase.

Ligyrion

Ligyrion is the first stone in row three of the breastplate.

Although ancient literature consistently indicates that ligyrion is amber, a fossilized tree resin, it has also been translated as “zircon,” “tourmaline,” and “opal.” The ancient Greeks knew ligyrion as elektron and were aware of its electrostatic properties. Rubbing ligyrion with wool cloth produces a strong negative electrostatic charge that attracts feathers and other light, positively charged materials.

Theophrastus writes that elektron is found in Liguria, an area of northwestern Italy and southeastern France, where it is “dug from the earth” and “has the power of attraction.” Other writers use the words elektron and ligyrion interchangeably.

In his Naturalis Historia, Pliny notes the sources of ligyrion, which he calls sucinum, as Liguria and the “northern sea” – the latter referring to the Baltic Sea coast. The Baltic coast supplied the Roman Empire with large quantities of amber and remains the world’s most prolific amber source.

Some biblical historians have translated ligyrion as yellowish or brownish zircon; others as tourmaline, likely because of tourmaline’s electrostatic properties. But neither zircon nor the tourmaline-group minerals were used as gemstones during the first millennium B.C.E., whereas amber was common. Harrell believes that ligyrion is definitely amber.

Achates

Achates is the second stone in row three of the breastplate.

Achates has usually been translated as “agate,” which is almost certainly correct. In On Stones, Theophrastus discusses achates as “a handsome stone from the river Achetes in Sicily that fetches a high price.” The Achetes River (now the Drillo River) is the root of the English word “agate” and a classic agate locality.

Pliny describes different colors and patterns of achates, all of which fit agate. He also writes that achates “was once held in high esteem, but now enjoys none,” apparently indicating that formerly valuable translucent and opaque gemstones had fallen out of favor in Rome by the first century C.E. and had been replaced by transparent stones from India.

Amethystos

Amethystos is the third stone in row three of the breastplate. (row three, third stone)

The Greek word amethystos, the root of the English word “amethyst,” has been translated only as amethyst and has no conflicting identifications. Amethystos means “without drunkenness;” the stone was believed to prevent drunkenness or to alleviate its unpleasant aftereffects.

Theophrastus discusses amethystos as “transparent … with the color of red wine … and found by splitting certain rock.” This description fits amethyst, because red wine is actually purplish-red, and amethyst often occurs in geodes that must be “split.” Pliny describes the stone as “violet” and notes that it comes from Egypt, where the Abu Diyeiba mine produced amethyst throughout the first millennium B.C.E. The ancient descriptions of amethystos can only fit amethyst.

This story about gemstones of the Bible previously appeared in Rock & Gem magazine. Click here to subscribe! Story and photos by Steve Voynick.

The post Gemstones of the Bible first appeared on Rock & Gem Magazine.

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• Nevada’s Carlin Trend: America’s Greatest Gold-Mining District. By Steve Voynick

• 10 Fascinating Facts About Opal: Celebrating October’s Captivating Birthstone. By Antoinette Rahn

• Claim to Copper Fame: Butte, Montana’s Colorful History of Becoming “The Richest Hill on Earth.” By Bob Jones

• Castanea Corals: Abundant Fossils from a Silurian Coral Reef. By Robert Beard

• Something New In Biggs Junction: Exploring a New Deposit Discovering in North Central Oregon. By Jim Landon

• Captivating Find at Carver Agate Field: Geologic Agate Mystery Draws Interest. By John L. Carver and Bill Halepeska

In addition, you’ll find the following regular R&G columns: Bench Tips with Bob Rush, Rock Science with Steve Voynick, What to Cut with Russ Kaniuth, On the Rocks with Bob Jones, Rock & Gem Kids and Earth Science In the News with Jim Brace-Thompson, Sneak Peek: Opals, The Road Report with Helen Serras-Herman, Picks & Pans, Show Dates, and the always popular Parting Shot.

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The post Issue Highlights: October 2020 first appeared on Rock & Gem Magazine.