Physical and Chemical Properties of Minerals
Minerals have their own specific physical and chemical properties that are dependent on compositions and combinations of constituent elements. These properties are used as indicators to determine mineral species.
In general, the solid crystalline minerals show properties that can be easily recognized by human senses such as color, luster, taste, odor, cleavage and fracture. Others should be measured or determined using special tools or instruments. Such properties include specific gravity, hardness, thermal conductivity and refractive index.
Chemical compositions and crystal structures of minerals give them various crystallographic, chemical, physical or optical characteristics. There are many interesting phenomena of minerals like polymorphism, isomorphism, exsolution or fluorescence. Minerals, the most abundant solid materials on earth, are of great use to us through a good understanding of their physical and chemical properties.
USA
Smoky quartz is characterized by dark gray to black color, attributed to defects in crystal structure. Smoky quartz is sometimes used as a semiprecious gemstone.
Aragonite
Aragonite is a polymorph of calcite, which means that it has the same chemistry as calcite but it has a different crystal structure, and more importantly, different symmetry and crystal shapes.