Boulder Opal look-alikes
Hydrated amorphous silica (SiO2·nH2O) in ironstone matrix
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Open the appSeveral rocks and minerals can be confused with Boulder Opal. Below are documented look-alikes and the features that tell them apart. Never rely on a single feature. Always check multiple properties.
Similar rocks to compare
Black Opal
Hydrated amorphous silica (SiO2·nH2O) with dark body tone
Also known as: Dark Opal
White Opal
Hydrated amorphous silica (SiO2·nH2O) with light body tone
Also known as: Light Opal
Crystal Opal
Hydrated amorphous silica (SiO2·nH2O) with transparency
Also known as: Transparent Opal
Common Opal
Hydrated amorphous silica (SiO2·nH2O) without play-of-color
Also known as: Potch Opal
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