
not a rock (man-made origin)
Blue Sea Glass
Amorphous Silica (Anthropogenic glass)
Hardness: 5-6 Mohs. Color: Deep teal/blue (likely derived from cobalt or copper additives). Luster: Vitreous when wet, often frosted/matte when dry. Crystal Structure: Amorphous (non-crystalline). Cleavage: Conchoidal fracture. Specific Gravity: ~2.4–2.8.
- Hardness
- 5-6 Mohs
- Luster
- Vitreous when wet, often frosted/matte when dry
Identified More not a rock (man-made origin) →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-6 Mohs. Color: Deep teal/blue (likely derived from cobalt or copper additives). Luster: Vitreous when wet, often frosted/matte when dry. Crystal Structure: Amorphous (non-crystalline). Cleavage: Conchoidal fracture. Specific Gravity: ~2.4–2.8.
Formation & geological history
Formed from discarded glass bottles or tableware that ended up in the ocean. Over years or decades, the movement of waves and abrasive action of sand tumbles the glass, rounding its edges and chemically etching the surface to create a matte finish.
Uses & applications
Commonly used in jewelry making (wire wrapping, pendants), beach-themed home decor, and as a popular item for collectors and beachcombers.
Geological facts
Certain colors indicate age; deep blue glass often comes from vintage poison bottles, medicine bottles (like Noxzema or Bromo-Seltzer), or decorative jars from the late 19th and early 20th centuries.
Field identification & locations
Identify by its frosted 'c-shaped' pockmarks on the surface (if genuine) and smooth, rounded edges. Often found on rocky or pebbly shorelines with high wave energy. Authentic sea glass should not have sharp edges or perfectly clear surfaces.
More like this
Other not a rock (man-made origin) specimens
Not a rock, mineral, or geological specimen
N/A
Dzi Bead (Etched Chalcedony)
Cryptocrystalline Quartz (SiO2) with chemical etching
mineral
Man-made Jewelry (Metal and Glass/Plastic)
Synthetic Alloy and Amorphous Solid (SiO2/Polymer)
not a rock
N/A - Non-Geological Item
not a rock/mineral
Slag Glass
Vitreous Silicate Residue
industrial byproduct (anthropogenic rock)
Ring with an Orange Inlay
N/A (Man-made object)
Man-made Object (Ring)