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Gemstones and Precious Stones

Geology and mineralogy of gemstones. To learn about actually working with gemstones, visit Tammy Powley's About Jewelry Making site. This page starts with individual gemstones from A to Z, then lists wider-ranging sites.

Get Closer to Gemstones
An introduction to the gemstone world and those who inhabit it.

Gemstone Names and Mineral Names
Two tables: gems listed with their mineral names, and minerals listed with their gem varieties.

Top 10 Gemstone Special Effects
The most important optical effects in gemstones, from fire to asterism.

Special Effects Picture Gallery
Examples of the most significant "special effects" found in gemstones (and other minerals).

Natural Gemstones
A good introduction to gemstone geology from the U.S. Geological Survey.

Geo-Quiz Number 25: Gems
Who wants to be a geo-whiz? The trivia game: GEMS

Agate (Chalcedony)
An introduction to this semiprecious stone of scientific interest and infinite visual variety.

Amazonite (Microcline)
Potassium feldspar sometimes makes a deep-green gemstone.

Amber Home Page
This "World of Amber" site by Susie Ward Aber of Emporia State University is the best out there when it comes to the scientific side.

Amber Project
Mark Meyer has amassed many amazing photos of amber and the fossils trapped in it.

Amethyst (Quartz)
Purple quartz is a popular gemstone.

A rare curiosity with an unusual deep blue color.

Carnelian (Chalcedony)
A big stone in an Iranian silver ring.

Diamond Specimen
A natural diamond crystal.

Diamonds: Gems from the Earth's Mantle
Diamonds are erupted directly through the crust from the crushing, red-hot bottom of the lithosphere.

Conflict Diamonds
The world's most beloved gem has a problem: contraband stones are funding crime, oppression and terrorism.

Gold Nugget
The real thing, from Alaska.

The Gold Rushes
There have been four American gold rushes, not just the one in California.

Labradorite (Plagioclase Feldspar)
The gem variety of plagioclase has dazzling blue schiller.

Lapis Lazuli (Lazurite)
This blue mineral is also the source of ultramarine.

Mandarin Garnet (Spessartine)
These honey-colored crystals are the same mineral as the red-orange gemstone.

Peridot (Olivine)
This olivine grain has the same green color as its gemmy version, peridot.

Some spectacular closeups of fire opal with notes on its mineralogy, from the About Geology Mineral Gallery.

Platinum Nuggets
This precious metal occurs in rare crystals.

A minor gemstone also called raspberry spar.

Rock Crystal (Quartz)
Brown, yellow and purple varieties are also gemstones.

Ruby (Corundum)
A fat crystal has the right color but is far from gemmy.

Sapphire (Corundum)
Even when it isn't gemmy, corundum makes good specimens.

A specimen of this semiprecious gem in its natural form, a page in the About Geology Mineral Gallery.

Probably no gemstone has more variety of color and pattern than the tourmaline. GGGems.com has a page of geologic information, studded with photos of natural crystals from Madagascar.

Tsavorite (Grossular Garnet)
Most grossular is not tsavorite's brilliant green or hessonite's warm orange. This is in between both.

This gemstone is truly precious to geologists for the data it yields.

Colored Stone Magazine
This bimonthly journal covers the world's high-end gem industry and also has articles and links of more general interest.

Gemological Institute of America
This prestigious organization has educated the trade since 1931. Its site has some high-grade articles on the frontiers of diamond research and other precious stones.

Gem Notes for Geology 347
Thorough, well-organized notes for Mark Helper's course at the University of Texas covers the common gems in depth.

Barbara Smigel's Free Gemology Course
This wonderful site is a free hard-core education in the basics of gemstones from gemologist Barbara Smigel.

Gemology and Lapidary Pages
"A comprehensive introduction to gemology and the lapidary arts" from Ray Elsey's amazing Tradeshop site.

The Gemstones
The first and still the best commercial site, The Mineral Gallery, gives you the gems with mineralogical rigor.

Pala Gems Learning Vault
Articles and buying guides from the experts make for a deep and tantalizing resource on precious stones.

Production of Specific U.S. Gemstones
The Bureau of Mines presents this overview, with pictures, of where the finest gems in the United States come from.

Ruby & Sapphire
A dazzling collection of articles on precious stones by Richard Hughes, who has lived the life.

Smithsonian Gems
A selection of the Smithsonian Institute's spectacular mineral and gem collection, starting with the Hope diamond.

What Is Shungite?
The 'magic mineral' shungite is interesting, but not as special as all that.

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