Wood Opal

Wood Opal is opal formed from silicified wood, recognized by a wood-like internal structure and earthy color patterns. In the hand, a good piece can look less like a conventional crystal and more like a preserved fragment of old timber, with browns, blacks, and greens held under a vitreous surface.

Mineralogically, Wood Opal is a variety of opal with the formula SiO2·nH2O. It is amorphous, translucent, non-magnetic, and has a white streak, with a Mohs hardness of 5.5-6.5 and density of 1.98-2.20 g/cm3.

Wood Opal takes its name from its resemblance to wood, and it has been known since the early 20th century. The name is practical and visual: collectors use it for opal that still carries the look of wood grain or internal wood structure after silicification.

For labeling and locality checking, collectors often compare specimen information with locality databases such as mindat.org. That is especially useful with Wood Opal because the material can be valued not only for opal color play, but also for how clearly it preserves the original wood-like pattern.

Wood Opal is found in the USA, Australia, and Brazil, most commonly in sedimentary deposits. Notable localities include Opal Butte in Oregon, USA; Lightning Ridge in New South Wales, Australia; and Cachoeira do Sul, Brazil.

Wood Opal forms when silica-rich water permeates wood and replaces the organic material with opal over time. The result is a mineral specimen that keeps a wood-like appearance while becoming opal, rather than remaining ordinary organic wood.

That replacement process explains why identification is so tactile and visual: the specimen may carry internal structure resembling wood, but its luster is usually vitreous and its fracture is conchoidal. Common impurities include iron and manganese, which may contribute to the natural character of the piece.

Identify Wood Opal by looking for wood-like internal structure combined with opal features. Typical colors are brown, black, and green, the luster is usually vitreous, and better pieces may show color play typical of opals.

A practical check starts with the basics: Wood Opal is amorphous, translucent, non-magnetic, and leaves a white streak. It has no birefringence or pleochroism, is isotropic, and has a refractive index of 1.44-1.46, with Mohs hardness of 5.5-6.5.

There are no known health risks associated with handling wood opal.

Rough/Tumbled: $10 - $50 per specimen

Cut/Polished: $20 - $100 per carat

Price is affected by color intensity and patterns.

Moderate — Scratch resistance: Fair, Toughness: Good

It can be sensitive to heat and sudden changes in temperature.

Use & Storage

Store in a cool, dry place away from direct sunlight.

Cleaning

Clean with a soft cloth and mild soap. Avoid abrasive cleaners.

Cleanse & Charge

Leave it under moonlight for cleansing.

Placement

Ideal for display in a cabinet or as part of jewelry.

Caution

Avoid prolonged exposure to moisture to maintain quality.

In crystal healing traditions, Wood Opal is believed to support emotional healing and grounding. Its listed qualities are grounding, healing, and stability, which suits the feel of the stone: earthy, calm, and visually rooted in the look of preserved wood.

Wood Opal is associated with the Root and Heart chakras, Taurus and Libra, Venus, and the Earth element. Use it as a meditation, relaxation, or inner-peace stone if that symbolism resonates, but do not use it as a substitute for medical treatment.