QUARTZ (var. PETRIFIED WOOD)

HISTORY, NAME, LOCALITIES: Petrified wood has been known since antiquity.  The word “petrified” comes from the Greek petros, meaning “stone,” and alludes to the replacement of wood by silica.  Petrified wood is found worldwide, with important sources in Madagascar, Libya, Namibia, Mongolia, China, Australia, and the United States (Arizona, California, Colorado, South Dakota, North Dakota, Wyoming).

MINERALOGY, PROPERTIES, OCCURRENCE: Petrified wood consists of interlocked microcrystals of quartz [silicon dioxide, SiO₂].  It is translucent to opaque and exhibits an extremely wide range of colors, notably deep reds, red-browns, and yellows, and often exhibits attractive, multicolored patterns.  Microcrystalline quartz is a tectosilicate or framework silicate with a Mohs hardness of 6.0-7.0, conchoidal fracture, and a specific gravity of 2.62-2.66.  Petrified wood forms in sedimentary deposits when tree structures are buried, preserved from aerobic decay, and become silicified through contact with silica-rich groundwater.

METAPHYSICAL PROPERTIES, LORE, USES: Stone Age cultures used petrified wood to manufacture tools and weapons.  In medieval times, amulets of petrified wood were thought to impart longevity.  Petrified wood serves as a popular gemstone and decorative stone.  Metaphysical practitioners believe that petrified wood provides an ancient and stable energy that connects with nature, assures longevity, and provides the power, wisdom, and patience needed to maintain spirituality in the everyday world.

COLLECTORS’ INFORMATION: Petrified wood is collected for its wide range of colors, ornate patterns, and frequent resemblance to original tree structures and shapes.