Smoky quartz
On the label: Smoky quartz · Gemstone
What it is
Brown to grey quartz, colored by natural or lab irradiation; Mohs 7.
Gemstones: Natural gemstones, as mined and cut. Hardness (Mohs scale) says what scratches what; treatment (heat, oil, dye) must be disclosed under FTC rules.
Wikidata: Facetted smoky quartz gemstone, 848g, found at Diamantina, Brazil. Q29791246 →
In the research
No PubMed papers mention this material with jewelry, allergy or eyewear; that is usual for findings and trade terms.
Other gemstones
Clasp & Lens describes materials from the public record and does not appraise, grade or test pieces; what a listing states is the supplier's statement. If a piece causes a rash, take it off; a reaction that spreads or blisters is a doctor's question, and sunglasses are no substitute for impact-rated eye protection where that is required.