Man-made material (Anthro-lithic product)
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various metal oxide impurities
Hardness: 5.5-6 (Mohs scale); Color: Pale light blue-green (Aqua); Luster: Frosted, matte, or satiny due to pitting; Crystal Structure: Amorphous (non-crystalline); Cleavage: Conchoidal fracture; Specific Gravity: 2.4-2.8.
- Hardness
- 5
- Color
- Pale light blue-green (Aqua)
- Luster
- Frosted, matte, or satiny due to pitting
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Physical properties
Hardness: 5.5-6 (Mohs scale); Color: Pale light blue-green (Aqua); Luster: Frosted, matte, or satiny due to pitting; Crystal Structure: Amorphous (non-crystalline); Cleavage: Conchoidal fracture; Specific Gravity: 2.4-2.8.
Formation & geological history
Formed through 'sea-tumbling' where discarded glass objects undergo decades of hydration and mechanical erosion in saltwater environments. The frosting is caused by a chemical process over 20-40 years where alkali is leached from the glass surface, leaving tiny pits.
Uses & applications
Primarily used in jewelry making (pendants, rings), mosaic art, home decor, and as a popular focus for beachcombing hobbyists.
Geological facts
Genuine sea glass is increasingly rare due to the global shift from glass to plastic packaging. The most common colors are green, brown, and clear, while colors like aqua, red, and orange are highly sought after by collectors.
Field identification & locations
Identify in the field by its distinctive 'frosted' surface, rounded/worn edges, and the absence of shiny internal fractures. Common locations include rocky beaches or tidal areas near historic ports or dumping sites. Collectors look for 'hydration marks' (tiny C-shaped pits) to verify authenticity.
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