Use the description precisely
Obsidian is volcanic glass. Its natural formation does not make it a crystalline mineral, and the word glass does not automatically mean a manufactured imitation. The US Geological Survey describes obsidian as dense volcanic glass, typically black. When reading about gemstone jewellery, this is a useful example of why natural origin and material structure should be considered separately.
Avoid identifying by darkness
A black polished pendant could contain several different materials. Colour and shine alone cannot distinguish obsidian from every other dark stone or manufactured glass. Ask what the seller identifies and what supports that description. If an unknown inherited piece is involved, professional examination is more useful than a home scratch, impact or heat test that could damage it.
Read decorative names carefully
A name evoking a colour, pattern or sheen may describe an appearance rather than provide a complete material identification. Keep that language beside the stated composition, not in place of it. Nor does the word volcanic establish a particular collection locality. Ask for evidence if a specific geographical source is presented as part of the piece's story or purchasing appeal.
Choose the finished design
Compare the actual surface, edge treatment, dimensions and relationship with its setting. A plain dark form can contribute visual contrast without needing invented rarity or performance claims. For CIELA jewellery, rely on the stated materials of the selected item. General knowledge about obsidian helps make descriptions clearer; it should not be used to relabel a black-looking stone in a photograph.
Further reading: US Geological Survey.
