mineral and glass

Pearl and Garnet Glass

Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass

AI-generated identification · may be incorrect

Pearl: Hardness 2.5-4.5, white/cream color, pearly luster, amorphous/organic. Glass: Hardness 5-6, deep red, vitreous luster, amorphous structure.

Identified February 24, 2026More mineral and glass →

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Physical properties

Pearl: Hardness 2.5-4.5, white/cream color, pearly luster, amorphous/organic. Glass: Hardness 5-6, deep red, vitreous luster, amorphous structure.

Formation & geological history

Pearls are organic gems formed inside mollusks over 1-3 years. The red material appears to be synthetic glass or garnet-colored resin mimicking metamorphic minerals.

Uses & applications

Primary use is in fashion jewelry and personal adornment.

Geological facts

Pearls are the only gemstones made by living creatures. Red glass has been used since ancient times to imitate expensive rubies and garnets.

Field identification & locations

Identify pearls by the 'tooth test' (gritty texture on teeth). Identify glass by looking for round bubbles or lack of natural inclusions under magnification and its warmth to the touch compared to stone.