Mineralogy classified into density (often given as specific gravity); measures of mechanical cohesion (hardness, tenacity, cleavage, fracture, parting); macroscopic visual properties (luster, color, streak, luminescence, diaphaneity); magnetic and electric properties; radioactivity and solubility in hydrogen chloride (). "Hardness" is determined by comparison with other minerals. In the Mohs scale, a standard set of minerals are numbered in order of increasing hardness from 1 (talc) to 10 (diamond). A harder mineral will scratch a softer, so an unknown mineral can be placed in this scale by which minerals it scratches and which scratch it. A few minerals such as calcite and kyanite
Tantalcarbide tools, or cermet. Tantalcarbide Tantalcarbide is a rare mineral of tantalum carbide with formula TaC. With a molecular weight of 192.96 g/mol, its primary constituents are tantalum (93.78%) and carbon (6.22%), and has an isometric crystal system. It generally exhibits a bronze or brown to yellow color. On the Mohs hardness scale it registers as a 6-7. Tantalcarbide is generally found in a granular state. It is extremely dense at 14.6 g/formula_1. Sub-conchoidal fracturing is exhibited. Specimens are extremely rare in nature. It is the only known mineral to exhibit the composition of TaC. Tantalum carbide powder is used for