Moss Opal

Dendritic Opal

A variety of Opal

What is Moss Opal?

Moss Opal is a type of common opal (not a precious variety) that is highly popular as a tumbled stone. Its popularity comes from its interesting, tree-like or fern-like inclusions of iron or manganese oxide. These inclusions are usually black but can exhibit bluish or gray shades. Thanks to its hardiness, moss Opal is often used in jewelry.

Optical Properties

Refractive Index
1.37-1.52
Pleochroism
None
Optical Character
Isotropic

Market Value Factors

Pricing varies for every rock and mineral, so use these universal factors to gauge Moss Opal before comparing listings or appraisals.

Size & Weight

Larger, intact specimens usually command higher prices.

Rarity & Demand

Scarce material or popular varieties sell at a premium.

Condition & Finish

Chips, repairs, and heavy wear lower value; clean prep helps.

Treatment & Provenance

Untreated specimens with documented locality are prized.

Applies to all rocks & minerals.

Moss Opal Localities Map

See where Moss Opal is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

Map preview
North ZoneCentral RidgeSouth Basin

Interactive map layers and collecting notes are available in the app.

Quick Facts

Physical Properties

Color
White, Black
Density
1.9 - 2.3 g/cm³
Streak
White

Chemical Properties

Chemical Formula
SiO2 · nH2O
Elements
H, O, Si
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Moss Opal FAQs

How do I identify Moss Opal?

Moss Opal can be identified by its White color. Look for these key characteristics when examining specimens.

What color is Moss Opal?

Moss Opal typically appears in White, Black. Color can vary depending on impurities and formation conditions.

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