What is in the cluster
- Jeweler loupe. Confirm hexagonal prisms vs cubes, growth striations, inclusions, facet junctions. 10× is the usual jeweler magnification.
- Mohs hardness kit. Webmineral: quartz 7, fluorite 4. Handbook of Mineralogy quartz PDF records hardness 7. That gap is the table split. Color waits.
When the stone is unnamed, or a label says “citrine” and you have not checked habit and hardness, this kit belongs. GIA: most citrine is heated amethyst. Still SiO2. USGS: obsidian is volcanic glass; do not start that one on a Mohs pick. Walk the checklist on How to identify a mineral specimen. The comparison with display gear is ID kit vs display stand.