Mineraloid (Anthropogenic/Man-made rock)

Sea Glass (specifically Frosted White)

Amorphous Silica (substance: Sodium-calcium silicate glass)

Hardness: 5.5-6.0 on Mohs scale; Color: Translucent white/frosted; Luster: Vitreous to dull (frosted); Crystal Structure: Amorphous (none); Cleavage: Conchoidal; Features: Smooth, rounded edges with surface pitting (C-shaped hydration marks).

Hardness: 5
Color: Translucent white/frosted
Luster: Vitreous to dull (frosted)

Identified April 11, 2026More mineraloid (anthropogenic/man-made rock) →

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Physical properties

Formation & geological history

Formed from man-made glass waste tumbled in oceans, seas, or large lakes for 20-50 years. Mechanical weathering from waves and chemical weathering from saltwater create the frosted surface.

Uses & applications

Used in jewelry (necklaces, earrings), mosaic art, home decor, and as a popular beachcomber's collectible.

Geological facts

Genuine sea glass undergoes a process called hydration, where leached alkali from the glass reacts with the water to create the signature frosted appearance. Rare colors include red, orange, and yellow, which come from vintage tableware or boat lights.

Field identification & locations

Identify by looking for frosted surfaces that lack sharp edges and have tiny 'C' shaped pits under magnification. Commonly found on pebble-strewn beaches near historic coastal towns or dump sites.

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