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
Geo-Mineral Exploration Corporation Geo-Mineral Exploration Corporation Geo-Mineral Exploration Corporation is an environmentally-sensitive exploration, acquisition, and merger company, which examines the viability of consolidating historic underground mining properties into small-scale specialty production alliances. The Geo-Mineral Corporation and its independent affiliates, are fully American-owned and operated. The Geo-Mineral Exploration Corporation was formed in 1968, as a limited partnership of twelve mining-industry professionals. In 1969, with claims to three properties in hand, the Geo-Mineral partnership converted all shares to simple, and preferred stock certificates, as the board unanimously voted to change its structure into that of a Corporation. Geo-Mineral Exploration Corporation (also known as Geo, Geomineral,