The name may be derived from the Latin word spinella, meaning "little thorn", possibly referring to the fact that some spinel crystals are found with sharp points. Spinel is almost a secret among gem lovers. It's hardness of 8, and lack of cleavage makes for a tough and durable gemstone. It mimics corundum, and crystals are found in a wide spectrum of colors, including red, orange, yellow, dark green, blue, purple, brown and black.
Preciosa offer an excellent black colour which is supported with ideal characteristic for wax casting. Heat resistance of this material is up to 1100°C/2012°F.
Opaque, jet-black variety of natural spinel
Chemical Composition: MgO.(Fe,Al)2O3
Hardness (şMohs): 7,5 - 8
Refractive Index: not measured - black
Dispersion (C-F): not measured - black
Heat Resistance: up to 1200°C / 2192°F
8.4.2008 23:56:33 | read 9499x