Quartz Data

Quartz is a very common rock-forming mineral.

Color: highly variable, from clear/colorless to purple (amethyst), pink (rose quartz), yellow (citrine), gray (smoky quartz), white (milky quartz), et cetera

Luster: glassy

Diaphaneity: transparent to translucent; may appear to be opaque in some hand specimens

Hardness: 7

Specific gravity: 2.65

Cleavage/fracture: fractures "conchoidally" along irregular-shaped surfaces

Other distinguishing properties:Quartz is harder than, and lacks the planar cleavage of, other minerals it might be mistaken for, including fluorite (which typically fluoresc es in UV light), calcite (which fizzes in dilute hydrochloric acid), halite (which tastes like salt), and gypsum (which is soft enough to be scratched by a fingernail).

Specimen Pictures


Klein, C., and Hurlbut, C.S., Jr., 1999, Manual of Mineralogy (after James D. Dana) [21st edition, revised]: New York, John Wiley & Sons, 682 p.

Los Angeles County Museum of Natural History, The Photo Atlas of Minerals: nhm.org/pam/

Return to the Minerals page.

The original content of these web pages is 2002 by Vince Cronin. It may be used for non-profit educational and research purposes only.