Copper
Though Copper is not theoretically a gem, it is included here due to its use in jewelry and as ornamental spheres. Copper had been one of the first metals become worked into implements and the steel that is first be smelted from ores. It absolutely was known to a few of the oldest civilizations on record and has a previous reputation for use that are at least 10,000 years old. It is estimated that Copper was first found around 9000 BC in the centre East, possibly northern Iraq. A copper pendant ended up being discovered in what is Iraq that has become northern that to about 8700 BC. It has been used in the making of tools, jewelry and ornamental pieces since ancient times and continues to be today that is popular. It is very malleable and contains exemplary ductility and conductivity that is high. This causes it to be valuable in industrial and electronics uses also.
Copper occurs in many localities worldwide. Some of the many notable are the deposits of the Keweenaw Peninsula, Keweenaw and Houghton Counties, Michigan, USA; in several copper deposits in Arizona, USA including those during the New Cornelia mine, Ajo, Pima County; the Copper Queen mine at Bisbee, Cochise County; as well as Ray, Gila County, Arizona.
| Crystallography: | Isometric – Hexoctahedral |
| Crystal Habit: | As cubes, dodecahedra, and as tetrahexahedra; rarely as octahedra and complex combinations. Commonly flattened on [111], elongated along [001]. Also as irregular distortions, in twisted, wirelike shapes; filiform, arborescent, massive; as a coarse powder. Masses weighing hundreds of tons have been found; crystals up to 15 cm. |
| Twinning: | On [111] to produce simple contact and penetration twins and cyclic groups. |
| Cleavage: | None Observed |
| Fracture: | Hackly, Jagged |
| Tenacity: | Highly Malleable and Ductile |
| Hardness (Mohs): | 2.5 – 3.0 |
| Density: | 8.94 – 8.95 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Highly Conductive |
| Color: | Copper-Red; tarnishes to Black or Green in air |
| Transparency: | Opaque |
| Luster: | Metallic |
| Refractive Index: | R: (400) 45.0, (420) 47.9, (440) 51.3, (460) 54.4, (480) 56.9, (500) 58.9, (520) 60.5, (540) 63.0, (560) 70.5, (580) 86.1, (600) 95.9, (620) 98.4, (640) 98.7, (660) 98.7, (680) 98.7, (700) 98.7 |
| Birefringence: | None; Opaque |
| Pleochroism: | None |
