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 Philosopher's Stone (Harry Potter, #1)

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Lists

The Story of Ruby Bridges by Robert Coles

The Hound of the Baskervilles by Arthur Conan Doyle

Characters with Jewel Names

260 books — 31 voters

Hey Hue-Man Where Is Our Food by Toni Crowe

To The Bright Edge of the World by Eowyn Ivey

Who Educates Parents? by Žilvinas Svigaris

The Travelling Cat Chronicles by Hiro Arikawa

Books that are under-appreciated gems.

388 books — 86 voters

Girl with a Pearl Earring by Tracy Chevalier

All That Sparkles Romances—Hero or Heroine is a Jewelry Designer, Jewel Thief, Gemologist, or in a Story About Jewels

176 books — 32 voters

Bedazzled Books

8 books — 2 voters

Lies My Teacher Told Me by James W. Loewen

Did You Hear What Eddie Gein Done? by Harold Schechter

Haven't You Heard? I'm Sakamoto, Vol. 1 by Nami Sano

My Library Has This?! Books You Were Shocked Appeared In A Library System.

14 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”

“ 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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“ As she descended below the floor level of the loft, her former partner in juvenile crime was revealed to her from scuffed paniolo boots, up a long, muscled body that appeared to go on forever, to a venerable black Stetson. His cowboy look was new to her and it suited him. When she backtracked to his Hawaiian-sky blue eyes, she swayed under the impact and abruptly sat down. Any stair step would do." Noelani Beecham, Pele's Tears ...more ”
― Sharon K. Garner, Pele's Tears

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