From rough
to records.
Last updated: August 2026
Straight answer first: photo apps can’t identify rough, and neither can we — but measured properties can. SG and hardness work on unpolished material; RI settles it once you’ve got a polished surface.
How a lapidary uses GemID
A labeled example workflow — honest about what each stage of material allows you to measure.
Triage the rough
Hydrostatic SG works on any solid piece, hardness on an inconspicuous spot, UV response in a dark room. Enter those three and the candidate list is usually short enough to decide whether the material is worth cutting.
Confirm after polishing
A refractometer needs a polished flat — so the RI reading that locks the identification comes after your first windows or facets. Enter it and watch the candidate list collapse.
Keep the record
One collection entry follows the piece from slab to finished stone: where it came from, what you measured at each stage, photos, weight, and what it’s worth to you.
The pieces that matter for lapidaries & rockhounds
How-to guides
Free technique guides — hydrostatic SG, refractometer use, UV testing — written for people doing the measurements themselves.
Reference charts
SG and hardness lookup tables for 130 species, free. Start from your reading and see every species in range.
Collection tracking
The material log: per-piece records with photos, measurements, and notes, organized by source or batch.
Natural vs. synthetic testing
The systematic checks worth doing before you spend hours cutting boule glass sold as rough.
The reference is free, the log is $6.99
Reference charts, how-to guides, and identification are free. The per-piece material log (saved sessions, photos, CSV import) starts at Hobbyist — $6.99/month or $49.99/year.
GemID identifies by measured properties and states results as “consistent with” — field results on rough material are indicators, not certifications. Read our full methodology.
Got a bucket of maybe-something?
Weigh a piece in and out of water, enter the SG, and see what’s in range.