SHATTUCKITE

HISTORY, NAME, LOCALITIES: Shattuckite was discovered and recognized as a new mineral species in 1915.  It is named for its place of discovery, the Shattuck Mine near Bisbee, Arizona.   Few localities produce good shattuckite specimens.  Notable sources are found in Austria, Democratic Republic of Congo, Greece, Namibia, and the United States (Arizona, California, Nevada, New Mexico).

MINERALOGY, PROPERTIES, OCCURRENCE: Shattuckite [basic copper silicate, Cu₅(Si₂O₆)₂(OH)₂], pronounced SHATT-uck-ite, is an inosilicate that crystallizes in the orthorhombic system as spherulitic aggregates of acicular crystals, as assemblages of fibrous crystals, and in massive form.  It has a Mohs hardness of 3.5, perfect cleavage in two directions, and a specific gravity of 4.1.  Crystals are translucent to opaque, have a dull-to-silky luster, and are dark-blue to light-blue and turquoise-blue in color.  Shattuckite is a secondary mineral that forms from the alteration of malachite and other secondary copper minerals and sometimes occurs as pseudomorphs after malachite.

METAPHYSICAL PROPERTIES, LORE, USES:  According to metaphysical belief, shattuckite is a stone of reconciliation that calms the mind to help ensure harmony in personal interactions.  Specimens of shattuckite in association with malachite have been polished for ornamental use.  Shattuckite has no technological uses.

COLLECTORS’ INFORMATION:  Shattuckite is collected for its rarity, color, unusual crystal forms, and association with malachite in composite specimens.

QUARTZ (var. ROCK CRYSTAL)

HISTORY, NAME, LOCALITIES: Rock crystal, which is common and occurs worldwide, has been collected since prehistory.  Notable collecting localities are found in India, Brazil, Germany, Peru, Bolivia, Namibia, Russia, and the United States (Arkansas, Colorado, Maine, Connecticut, Virginia).

MINERALOGY, PROPERTIES, OCCURRENCE: Rock crystal is the transparent, colorless variety of macrocrystalline quartz [silicon dioxide, SiO₂).  The word “quartz” is believed to have originated with the Slavic kwardy, meaning “hard,” in allusion to its substantial hardness.  It crystallizes in the hexagonal system and occurs mainly in hydrothermal veins, granite pegmatites, and as geode linings as short-to-long, horizontally striated, hexagonal, prismatic crystals with pyramidal terminations and distinctive, water-clear transparency.  It has a Mohs hardness of 7.0, a conchoidal fracture, vitreous luster, and specific gravity of 2.65.

METAPHYSICAL PROPERTIES, LORE, USES: Rock crystal has since antiquity been one of the most widely collected of all minerals.  It has served as a gemstone and ornamental stone in many cultures.  Until quartz was synthesized in the 1960s, rock crystal was vital to electronic frequency controls, filters, and timing devices. Modern metaphysical practitioners call rock crystal the “universal crystal” because of its numerous abilities to sharpen insight, enhance spiritual development, improve concentration, refine focus, and energize the mind.

COLLECTORS’ INFORMATION: Rock crystal is widely collected for its brilliant transparency, superb hexagonal crystal development, and frequent occurrence on large plates and in geodes to make interesting display pieces.