Barbara Smigel, PhD. GG
ContributorBarbara Smigel is a GIA certified gemologist, facetor, jewelry designer, gem dealer, gemology instructor and creator of the well-regarded educational websites acstones.com and bwsmigel.info.
Articles by Barbara Smigel, PhD. GG
Chrysoprase Value, Price, and Jewelry Information
Chrysoprase is apple-green chalcedony that derives its color from nickel. Its hardness and striking color make it a popular gemstone...
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Benitoite Value, Price, and Jewelry Information
With dispersion higher than diamond and sapphire-blue body color, benitoite is one of the most attractive of all rare gems....
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Pearl Value, Price, and Jewelry Information
Pearls are the only gems found within living creatures, both salt and freshwater mollusks. However, most pearls on the market...
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Red Beryl Value, Price, and Jewelry Information
Originally known as bixbite, red beryl is one of the rarest, most desirable, and most expensive gemstones. Most fine crystal...
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Morganite Value, Price, and Jewelry Information
A member of the beryl family, morganite shows a range of pink colors due to traces of manganese. Recently, this...
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Danburite Value, Price, and Jewelry Information
A very durable gemstone, danburite is an excellent choice for jewelry use. Although the mineral isn't rare, large facetable pieces...
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Spinel Buying Guide
Our spinel buying guide can help you learn how spinels are graded and how to identify a high-quality stone or...
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Sphene (Titanite) Value, Price, and Jewelry Information
Sphene, also known as titanite, has rich body colors, strong trichroism, and a fire that exceeds diamond. Although softer than...
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Oregon Sunstone Value, Price, and Jewelry Information
While feldspar sunstones from sources around the world have been used for carvings and cabochons, Oregon sunstone material has proven...
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Tanzanite (Zoisite) Value, Price, and Jewelry Information
Tanzanite has had a rapid rise to prominence among jewelers and gem enthusiasts. Although naturally reddish brown, this transparent zoisite...
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Apatite Value, Price, and Jewelry Information
Although too brittle for most jewelry use, properly cut apatite gems are truly magnificent. A collector could assemble a suite...
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Moldavite Value, Price, and Jewelry Information
An olive to bottle-green natural glass, moldavite is a rare material popular with collectors of unusual gems as well as...
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Andalusite Value, Price, and Jewelry Information
Strongly pleochroic, andalusite can show shades of green, brown, and red when viewed from different directions. Although tough enough for...
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Ametrine Value, Price, and Jewelry Information
Ametrine is a variety of quartz that displays bands of both amethyst purple and citrine yellow. These gems are typically...
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What is Moonstone Gemstone? Value, Price, and Color
Found all over the world, moonstone is prized for its blue to white adularescence — a billowy, moonlight-like sheen. Despite...
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Amethyst Gem, Price, and Jewelry Information
Amethyst is crystalline quartz in colors ranging from pale lilac to deep reddish purple. The February birthstone makes a fine,...
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Scapolite Value, Price, and Jewelry Information
Although not well known, scapolite would make an attractive gem material for both jewelry enthusiasts and mineral collectors. It comes...
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Malachite Value, Price, and Jewelry Information
Malachite is a beautiful decorative stone. Its rich, patterned coloration in shades of green is unique among gems. Malachite's low...
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Charoite Value, Price, and Jewelry Information
With light to medium dark purple colors and swirling patterns, charoite is usually quite distinctive. No other material is likely...
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Sphalerite Value, Price, and Jewelry Information
Sphalerite occurs in many colors. With a dispersion over three times that of diamond and an adamantine luster, faceted specimens...
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Lapis Lazuli Value, Price, and Jewelry Information
Lapis lazuli has been used since ancient times and remains popular today. This gemstone has been prized for its bright,...
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Rubellite Tourmaline Value, Price, and Jewelry Information
Rubellites are tourmalines with reasonably saturated dark pink to red colors and medium to dark tones. They make excellent jewelry...
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Topaz Gem, Price, and Jewelry Information
Topaz is a semiprecious gemstone made of aluminum and fluorine. Although frequently associated with golden yellow and blue, it can...
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Mali Garnet Value, Price, and Jewelry Information
One of the rarer varieties in the garnet group, Mali garnet is a blend of grossular and andradite. This gemstone...
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Emerald Value, Price, and Jewelry Information
Emerald has been synonymous with the color green since ancient times. A fine emerald is a truly breathtaking sight, and...
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Peridot Value, Price, and Jewelry Information
The modern August birthstone, peridot has been prized as a jewelry stone since ancient times. Always green in color but...
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Ruby Value, Price, and Jewelry Information
One of the most popular traditional jewelry stones, ruby is exceptionally durable. The colors of the July birthstone — always...
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Freshwater Pearls Value, Price, and Jewelry Information
Like their marine cousins, many freshwater mollusks can produce pearls. However, this rarely occurs in nature. Today, the majority of...
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Gemstone Doublets, Triplets, and Other Assembled Stones
Made from two or more materials, assembled gems can make durable and affordable jewelry. Learn more about gemstone doublets, triplets,...
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Zircon Value, Price, and Jewelry Information
Don’t be confused by the name. Zircon is a natural, magnificent, and underrated gemstone that has been worn and treasured...
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Citrine Value, Price, and Jewelry Information
Citrine is the yellow to red-orange variety of crystalline quartz. Clever marketing and the rise of “earth tone” fashions have...
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Spinel Gem, Price, and Jewelry Information
Although long known best for being misidentified as ruby, the spinel gem is beautiful in its own right. Its colors,...
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Chalcedony Value, Price, and Jewelry Information
Technically, chalcedony (kal SED' uh nee) is any form of microcrystalline or cryptocrystalline quartz, (meaning any form of quartz whose...
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Agate Value, Price, and Jewelry Information
Agate is a variety of chalcedony that exists in many colors and is often commercially dyed. Agate is distinguished by...
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Quartz Value, Price, and Jewelry Information
An overview on Quartz Jewelry and Gemstones. Covers details and essential information on the physical properties and characteristics of a...
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Fossilized Organisms
Most people who have an interest in gemstones or nature have seen petrified wood, but fewer are aware of the...
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Iolite Value, Price, and Jewelry Information
This stone, which represents one of the few relatively available and affordable blue stone options, is rapidly gaining in popularity....
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