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
Mohs (automobile) SafariKar was introduced in 1972, and was no less exotic than the Ostentatienne. SafariKars were aluminum bodied automobiles, the exterior of which were upholstered in Naugahyde (vinyl) stretched over foam padding. Doors for the vehicle opened outward from the body on linear rods, again for side impact protection. The vehicle had a retractable hard top system. Options for the SafariKar included a television, four-wheel drive, two-way radio and "butane furnace." Only three were produced, probably all in 1972 since an early Mohs publicity photograph shows all three in various stages of assembly. "Production" of the Safari Kar was listed in