Mohs is a scratch sequence. Identify before you name a species. USGS publishes the scale; IMA publishes species names.

Workflow, in order

  1. Streak, color of the powder on unglazed porcelain.
  2. Hardness, what it scratches, what scratches it, against the USGS Mohs sequence.
  3. Cleavage, how it breaks.
  4. Habit, the shape the crystal grew.

Then open Mindat or the IMA species list. See How to identify a mineral specimen.

Sources

  1. USGS. Mohs hardness scale.
  2. International Mineralogical Association.
  3. Mindat.org.