Identification & care

Identification is the part of crystal study most often skipped and the part that protects everything else. A practitioner who can run a hardness test, read a fracture surface, and recognise dye following a crack is not dependent on a seller’s label — which matters, because a great deal of material in the trade is mislabelled, and some of it is dyed calcite, reconstituted powder, or glass. None of that requires laboratory equipment to catch.

This section holds the working procedures: the hardness scale with everyday test materials, lustre and translucency comparisons, the difference between cleavage and fracture, and the specific substitutions to expect for each family. It also holds care notes, which are a safety matter as much as a preservation one — several popular minerals are water-soluble, a few are friable enough to shed dust that should not be inhaled, and others fade irreversibly in daylight. Sourcing notes are included where the origin of a material has a documented human cost.