iOS · Gemmology
A working bench for identifying stones — the notebook, the calculator and the reference table that sit next to your loupe.
Obsidian Codex is honest about its limits: bench testing narrows a stone down, it does not replace a laboratory report. What it does is stop you guessing, keep your reasoning on record, and make the next stone faster to work through than the last.
Work through a stone the way the bench actually works: colour, transparency, lustre, hardness, what the inclusions look like under magnification. As you fill in observations, the candidate list narrows, each match shows how confident it is, and conflicting results get flagged — which is usually where the real answer hides.
Enter dry weight and weight in water; the calculator does the rest. Units cancel out, so it does not matter whether you weigh in carats or grams.
Compare against the standard scale with practical guidance on what a scratch test does and does not prove, so you can use it without damaging a stone that deserves better.
Log every specimen with weights, dimensions, where and when you acquired it, what it cost and where it sits now. Attach photos and keep the test sheet with the stone, so the reasoning behind an identification stays attached to it.
Browse gem families with the properties that separate them — the ranges you would otherwise be flipping through a book to find, with the diagnostic details that actually matter at the table.
A visual grid of what different internal worlds look like, because a stone's inclusions are often the fastest honest answer.
Choose carats or grams, millimetres or inches once, and every weight and dimension in the drawer follows.
Everything stays on your device. No accounts, no tracking, no ads — just the bench.