Platinum (native)
Platinum is an exotic and expensive mineral that is rarely found as well formed crystals. It is typically found as placer nuggets, grains or as veins in host rock. Pure platinum is unknown in nature as it usually is alloyed with other metals such as Iron, Copper, Gold, Nickel, Iridium, Palladium, Rhodium, Ruthenium and Osmium. The presence of Iron can result in slight magnetism in the Platinum nuggets. The most common source of Platinum is placer deposits where the Platinum has weathered out of igneous rocks and tumbled down streams and rivers over many years. Placer deposits form in streams and rivers behind rocks where the heavier materials such as Platinum and Gold are deposited and are too heavy to be washed downstream.
Platinum is more rare than gold and is typically more expensive by weight than Gold. Chemically, Platinum is very non-reactive and can facilitate many chemical reactions without being altered in the process. It is used in many anti-pollution devices, especially catalytic converters. For this reason, it has been nick named the “Environmental Metal”.
Platinum is found in many deposits world-wide. In the Pinto River, near Papayan, in the Department of Chocó, Cauca, Colombia (the Type Locality). In the USA, from Platinum Creek, Goodnews Bay, Alaska; in California, in a number of placers, as in Trinity County; and at Oroville, Butte County In Oregon, at Cape Blanco, Port Orford, Curry County In Canada, at Rivière-du-Loup and Rivière des Plantes, Beauce County, Quebec; in British Columbia, in the Kamloops district, on the Fraser and Tranquille Rivers, and in the Similkameen district, on Granite, Cedar, and Olivine Creeks, tributaries to the Tulameen River; in Alberta, near Edmonton. In Russia, in the Ural Mountains, in a large district surrounding Nizhni Tagil; good crystals from the Konder massif, Aldan Shield, Sakha. In South Africa, at a number of deposits along the Merensky Reef of the Bushveld complex, Transvaal.
| Chemical Formula: | Pt | ||||||||||
| Platinum (Elemental Platinum) | |||||||||||
| Molecular Weight: | 195.08 gm | ||||||||||
| Composition: |
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| Crystallography: | Isometric – Hexoctahedral |
| Crystal Habit: | Cubic crystals, typically distorted, to 1.5 cm; commonly as grains or scales, rarely as nuggets or lumps up to 30 kg. |
| Twinning: | On {111}, as interpenetrant contact twins. |
| Cleavage: | None |
| Fracture: | Hackly |
| Tenacity: | Malleable and Ductile |
| Moh’s Hardness: | 4.0 – 4.5 |
| Density: | 14.0 – 19.0 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Nonmagnetic to distinctly magnetic when rich in iron. |
| Color: | Whitish Steel Gray, Steel Gray, Dark Gray |
| Transparency: | Opaque |
| Luster: | Metallic |
| Refractive Index: | R: (400) 60.5, (420) 62.3, (440) 63.8, (460) 65.1, (480) 66.3, (500) 67.5, (520) 68.6, (540) 69.5, (560) 70.2, (580) 70.7, (600) 71.2, (620) 71.6, (640) 71.8, (660) 72.1, (680) 72.4, (700) 72.8 |
| Birefringence: | 0.00 (Opaque) |
