Mineral Identification Score

The scoring formula doubles the weight of the hardness difference relative to luster and color, and weighs it more heavily than cleavage too, because Mohs hardness — tested with a fingernail (2.5), penny (3.5), glass (5.5), or steel file (6.5) — is generally the most discriminating and repeatable field test available without lab equipment. Color gets the smallest fixed penalty of any property since it's the least reliable identifier, varying with impurities and weathering even within a single mineral species.

Several minerals in the 17-entry reference table share similar hardness and luster profiles — quartz and topaz, or pyrite and magnetite, for example — so when your entered properties sit near both profiles, their weighted distances end up close together and produce nearly identical scores. A narrow gap between the top two matches is expected in these cases and is a signal to run an additional confirming test, like streak color, magnetism, or an acid-reaction test, rather than trusting the single top answer.

It's not a probability — it's your total weighted distance from a mineral's reference profile, subtracted from a theoretical maximum possible distance (31, from the worst-case mismatch across all four properties) and expressed as a percentage. A 100% score means your entered hardness, luster, cleavage, and color exactly match that mineral's profile in the table; lower scores mean one or more properties diverge, with hardness mismatches costing the most points.

The calculator only scores against 17 common rock-forming and ore minerals — talc through diamond on the reference table — so it will always return its three best matches from that fixed list even if your actual specimen isn't one of them. If your top three scores are all low, that's a sign the true mineral likely falls outside this reference table rather than a fourth or fifth candidate the tool is simply not showing you.