Mineraloid (Man-made)

Opaline Glass (Opalite)

Synthetic Silicon Dioxide Glass

Hardness: 5-5.5 on Mohs scale; Color: Milky white to translucent blue with orange/yellow 'glow' when light passes through; Luster: Vitreous (glassy); Crystal Structure: Amorphous; Cleavage: Conchoidal fracture.

Hardness: 5-5
Luster: Vitreous (glassy)

Identified March 25, 2026More mineraloid (man-made) →

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Physical properties

Formation & geological history

Opalite is a man-made variety of glass produced by melting dolomite and magnesium with silica. Unlike natural opal, it is manufactured in industrial settings rather than geological environments.

Uses & applications

Used primarily for decorative purposes, costume jewelry, healing crystals, and lapidary practice. It is popular among collectors of 'metaphysical' stones due to its aesthetic appeal.

Geological facts

Although often marketed as 'Sea Opal' or 'Moonstone,' it is entirely synthetic. It exhibits the Tyndall effect, which causes the blue coloration by scattering light, similar to why the sky appears blue.

Field identification & locations

Identify by looking for tiny air bubbles inside the material and a uniform 'glow' that natural opals lack. It will feel warmer to the touch than natural stone and lacks the specific 'fire' or play-of-color flashes seen in precious opal.

Other mineraloid (man-made) specimens

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Green Glass (often marketed as 'Obsidian' or 'Green Quartz')

Amorphous Silica (SiO2) with copper or chromium additives

Mineraloid (Man-made)

Opalite

Synthetic Opalite Glass (Silicon Dioxide)

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Synthetic Resin (Artificial Specimen)

Polyurethane or Polyester Resin

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Green Glass Slag

Amorphous Silicon Dioxide (SiO2) with metal oxide impurities

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Glass Nugget (Tumbled Glass)

Amorphous Silicon Dioxide (SiO2) with additives

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Opalite

Synthetically produced glass (Silicon Dioxide with metallic inclusions)

Mineraloid (Man-made Glass)