JET: Whitby, England (~3 each)
Jet has been known since Neolithic times and has been the most popular of all black gems. It has been used for many years in mourning jewelry. It is less popular and widely used in modern times. It takes a very good polish and is less brittle than the harder anthracite coal that it resembles. Jet is often faceted (the stones have a flat bottom) to add sparkle to the somber tones of jet jewelry.
Jet Value
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Jet Information
| Data | Value |
| Name | Jet |
| Crystallography | Amorphous. Usually in coal seams as black masses and lumps. |
| Colors | Black, brownish. |
| Luster | Dull; vitreous when polished. |
| Hardness | 2.4-4. Density: 1.19-1.35. |
| Cleavage | None. Conchoidal fracture. Brittle. |
| Stone Sizes | Carvings and cabochons of any desired size could be cut. |
| Formula | C. Carbon, plus impurities; not a mineral. |
JET: Whitby, England (~3 each)
Optics: Blurred shadow edge on refractometer at 1.66.
Other Tests: Burns like coal and gives burning coal odor with hot needle.
Occurrence: Jet is fossilized wood, actually lignite, a form of brown coal.
Henry Mountains, Utah; Colorado; New Mexico.
Spain; Aude, France; Germany; USSR; Poland; India: Turkey.
Whitby England: jet in seams; classic locality
Comments: Jet has been known since Neolithic times and has been the most popular of all black gems. It has been used for many years in mourning jewelry. It is less popular and widely used in modern times. It takes a very good polish and is less brittle than the harder anthracite coal that it resembles. Jet is often faceted (the stones have a flat bottom) to add sparkle to the somber tones of jet jewelry.
Name: Originally from Gagates, the name of a town and river (Gagae) in Asia Minor.
 | An Introduction To Turkey’s Gemstones |
