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
Pabstite minute fluid and solid inclusions. Its hardness is 6 on Mohs scale of mineral hardness. Its density is 4.03 g/cm and it is uniaxial. The interference colors of pabstite are anomalous blue-violet and golden yellow. The refractive indices of pabstite are ω = 1.685±0.002 and ε = 1.674±0.002 which result in low birefringence and absent dichroism. Pabstite was first described in 1965 for an occurrence in the Kalkar quarry of Santa Cruz County, California. The mineral was named for Adolf Pabst (1899–1990) a mineralogy professor at the University of California, Berkeley. Pabstite has also been reported from Tres Pozos, Baja