Gemstones

A gemstone (also called a gem, fine gem, jewel, precious stone or semi-precious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli) or organic materials that are not minerals (such as amber or jet) are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gems A gemstone (also called a gem, fine gem, jewel, precious stone or semi-precious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli) or organic materials that are not minerals (such as amber or jet) are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone. Apart from jewelry, from earliest antiquity engraved gems and hardstone carvings, such as cups, were major luxury art forms. A gem maker is called a lapidary or gemcutter; a diamond worker is a diamantaire.

The traditional classification in the West, which goes back to the ancient Greeks, begins with a distinction between precious and semi-precious; similar distinctions are made in other cultures. In modern usage the precious stones are diamond, ruby, sapphire, and emerald, with all other gemstones being semi-precious. This distinction reflects the rarity of the respective stones in ancient times, as well as their quality: all are translucent with fine color in their purest forms, except for the colorless diamond, and very hard, with hardnesses of 8 to 10 on the Mohs scale. Other stones are classified by their color, translucency and hardness. The traditional distinction does not necessarily reflect modern values, for example, while garnets are relatively inexpensive, a green garnet called tsavorite can be far more valuable than a mid-quality emerald. Another unscientific term for semi-precious gemstones used in art history and archaeology is hardstone. Use of the terms 'precious' and 'semi-precious' in a commercial context is, arguably, misleading in that it deceptively implies certain stones are intrinsically more valuable than others, which is not necessarily the case.

In modern times gemstones are identified by gemologists, who describe gems and their characteristics using technical terminology specific to the field of gemology. The first characteristic a gemologist uses to identify a gemstone is its chemical composition. For example, diamonds are made of carbon (C) and rubies of aluminium oxide (Al2O3). Next, many gems are crystals which are classified by their crystal system such as cubic or trigonal or monoclinic. Another term used is habit, the form the gem is usually found in. For example, diamonds, which have a cubic crystal system, are often found as octahedrons.

Gemstones are classified into different groups, species, and varieties. For example, ruby is the red variety of the species corundum, while any other color of corundum is considered sapphire. Other examples are the Emerald (green), aquamarine (blue), red beryl (red), goshenite (colorless), heliodor (yellow), and morganite (pink), which are all varieties of the mineral species beryl.

Gems are characterized in terms of refractive index, dispersion, specific gravity, hardness, cleavage, fracture, and luster. They may exhibit pleochroism or double refraction. They may have luminescence and a distinctive absorption spectrum. Material or flaws within a stone may be present as inclusions.

Gemstones may also be classified in terms of their "water". This is a recognized grading of the gem's luster, transparency, or "brilliance". Very transparent gems are considered "first water", while "second" or "third water" gems are those of a lesser transparency. ...more

Gemstones Books

A Court of Mist and Fury (A Court of Thorns and Roses, #2)

Harry Potter and the Deathly Hallows (Harry Potter, #7)

Harry Potter and the Sorcerer's Stone (Harry Potter, #1)

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Lists

Girl with a Pearl Earring by Tracy Chevalier

Night Night, Sleep Tight by Hallie Ephron

Pearls on the Cover

126 books — 17 voters

A String of Pearls

163 books — 10 voters

Best Jewel Thief Novels

51 books — 76 voters

How Green Was My Valley by Richard Llewellyn

King Solomon's Mines by H. Rider Haggard

Mining

150 books — 68 voters

Diamonds on Novel Covers

18 books — 4 voters

All I Wanted Was Sushi But I Got Abducted By Aliens Instead by Petra Palerno

"Opal"

41 books — 8 voters

Related Genres

Geology
Jewelry
Jewellery
Jewelry Making
Jewels

Minerals
Mineralogy
Lapidary
Jewellery Making
Petrology

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Quotes Tagged “Gemstones”

“ • Whatever anyone does or says, I must be good; just as if the emerald were always saying this: "Whatever anyone does or says, I must still be emerald, and keep my color. ...more ”
― Marcus Aurelius

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“ To my mind there is nothing like the quest for jewels at their sources, which will throw a man into the whirlpool of adventure, and if he has eyes to see it, into the arms of romance itself. Adventure and romance usually prove to be uncommonly uncomfortable at first-hand, but they are the stuff of memories. Memories studded with gems, memories literally bejeweled, are to me memories worth having indeed. ”
― Louis Kornitzer

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