AM-2020-10001-A · Chalcedonyarchived
physical & structuralrev. 4
| designation | Chalcedony |
|---|---|
| chemical formula | SiO₂ |
| classification | Tectosilicate / cryptocrystalline quartz |
| crystal system | Trigonal |
| mohs hardness | 6.5 – 7 |
| density (g/cm³) | 2.64 |
| colour | Faintly banded grey |
| type locality | Ouro Preto, Minas Gerais, Brazil |
raman spectroscopy532 nm · pass A
reported peaks (cm⁻¹): 130, 465, 501
notessubmitter remarks + registry
Photographic record retained. Specimen temperature held at lab ambient throughout intake.