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2. Agate - Wikipedia

   en.wikipedia.org/wiki/Agate

   Agate (/ ˈ æ ɡ ɪ t / AG-it) is a variety of chalcedony, [1] which comes in a wide variety of colors. Agates are primarily formed within volcanic and metamorphic rocks.The ornamental use of agate was common in ancient Greece, in assorted jewelry and in the seal stones of Greek warriors, [2] while bead necklaces with pierced and polished agate date back to the 3rd millennium BCE in the Indus ...

3. Lapis lazuli - Wikipedia

   en.wikipedia.org/wiki/Lapis_Lazuli

   Originating from the Persian word for the gem, lāžward, [1] lapis lazuli is a rock composed primarily of the minerals lazurite, pyrite and calcite. As early as the 7th millennium BC, lapis lazuli was mined in the Sar-i Sang mines, [2] in Shortugai, and in other mines in Badakhshan province in modern northeast Afghanistan. [3]

4. Nuummite - Wikipedia

   en.wikipedia.org/wiki/Nuummite

   Nuummite is a rare metamorphic rock that consists of the amphibole minerals gedrite and ... where it was found. [1] [2] [3] Description ... Gems and Gemology, 23, ...

5. Garnet - Wikipedia

   en.wikipedia.org/wiki/Garnet

   The mineral garnet is commonly found in metamorphic and to a lesser extent, igneous rocks. Most natural garnets are compositionally zoned and contain inclusions. [ 45 ] Its crystal lattice structure is stable at high pressures and temperatures and is thus found in green-schist facies metamorphic rocks including gneiss , hornblende schist , and ...

6. Tiger's eye - Wikipedia

   en.wikipedia.org/wiki/Tiger's_eye

   Tiger's eye (also called tiger eye) is a chatoyant gemstone that is usually a metamorphic rock with a golden to red-brown colour and a silky lustre.As members of the quartz group, tiger's eye and the related blue-coloured mineral hawk's eye gain their silky, lustrous appearance from the parallel intergrowth of quartz crystals and altered amphibole fibres that have mostly turned into limonite.

7. Jasper - Wikipedia

   en.wikipedia.org/wiki/Jasper

   Jasper breaks with a smooth surface and is used for ornamentation or as a gemstone. It can be highly polished and is used for items such as vases, seals, and snuff boxes. The density of jasper is typically 2.5 to 2.9 g/cm 3. [4] Jaspillite is a banded-iron-formation rock that often has distinctive bands of jasper.

8. Pegmatite - Wikipedia

   en.wikipedia.org/wiki/Pegmatite

   A metamorphic pegmatite would be formed by removal of volatiles from metamorphic rocks, particularly felsic gneiss, to liberate the right constituents and water, at the right temperature. A metasomatic pegmatite would be formed by hydrothermal circulation of hot alteration fluids upon a rock mass, with bulk chemical and textural change.

9. List of minerals - Wikipedia

   en.wikipedia.org/wiki/List_of_minerals

   Ammolite (organic; also a gemstone) Amosite (asbestiform grunerite) Antozonite (variety of fluorite) Anyolite (metamorphic rock - zoisite, ruby, and hornblende) Aquamarine (light blue variety of beryl) Argentite (high temperature form of acanthite) Asbestos (fibrous serpentine- or amphibole minerals) Auerlite (variety of thorite)