Chalcedony (agate-like, iron-stained) — mineral Identification & Properties | Geo-Gem
Chalcedony (agate-like, iron-stained) is a mineral. - Scratch test: try to scratch a piece of window glass (H~5.5). Chalcedony (H 6.5–7) should leave a clear scratch; opal may not. - Streak: on unglazed porcelain expect a white streak (quartz family). - Fracture: examine fresh chips—smooth,…