Hexagonal

Hexagonal

A secondary lead mineral found in the oxidized zones of lead deposits, this mineral is characterized by its crystal form, high luster, and high specific gravity. The name is derived from two Greek words meaning "fire" and "form" in allusion to the apparent crystalline form it assumes on cooling from fusion.

Discovered in 1860, this mineral is named from the Greek word "to deceive" as it was often confused with other minerals. It is widely disseminated as an accessory constituent in all classes of rocks: igneous, sedimentary, and metamorphic. Fluorapatite is by far the most common species of this mineral group.

This mineral was named from the German nickname for the ore miners called "kupfernickel' (copper nickel); after Old Nick and his mischievous gnomes, because the ore seemed to contain copper but yielded none. It is, however, a minor ore of nickel.

The principal ore of molybdenum, this mineral was named from the Greek word meaning "lead." Currently, this mineral is being researched as a possible replacement semiconductor for silicon transistors in electronic chips. It forms as an accessory mineral in granites and is commonly found in high temperature vein deposits and contact metamorphism.

Named in 1845 in honor of the English mineralogist ( ) William Miller (1801-1880) ( ) who first studied the crystals, this mineral forms as a low-temperature mineral often in cavities and as an alteration of other nickel minerals. It is commonly found as radiating and jack-straw clusters of shiny metallic acicular crystals, pale brass-yellow with an iridescent tarnish.

Discovered in 1840, this mineral was named for Lord Greenock (1783-1859). It is the most common mineral containing cadmium, but it is found only in a few localities and in small amounts, usually as an earth-coating on zinc ores, especially sphalerite. Cadmium is used in alloys for antifriction bearings, low-melting alloys, and in electroplating.

Discovered in 1832 and named after Niccolo Covelli (1790-1829), an Italian mineralogist and discoverer of the mineral at Mount Vesuvius, this mineral is characterized by its indigo-blue color. It is usually found as a secondary copper mineral in copper deposits and rarely occasionally as a volcanic sublimate.

This mineral is easily recognized by its red color and scarlet streak, high specific gravity, and cleavage. It is a low temperature hydrothermal mineral and the only important source of mercury. The name is from the Persian possibly meaning "dragon's blood."

Named after the Latin word for “alum”, this mineral is also called “alumstone.” It was discovered in Latium, Italy, in 1824 and is formed by sulfuric acid solutions acting on rocks rich in potash feldspar. In Marysvale, Utah, it has been mined and treated to recover potassium and aluminum.

Because of its solubility in water, this mineral is found only in arid and desert regions. In Chile, it is quarried, purified, and used as a source of nitrates. Nitrates are used in explosives and fertilizer.