# Rock and mineral field identification tests

Canonical page: https://lithomap.app/resources/field-tests
Last reviewed: September 18, 2026
Page purpose: Directory of original LithoMap procedures for obtaining and interpreting common physical-property evidence.

The collection covers six distinct methods without treating any one result as proof of identity. Each page explains the scientific principle, field kit, procedure, interpretation, representative guide examples, common errors, safety, FAQs, and authoritative sources.

## Method guides

- Mohs hardness test: A careful scratch comparison can place a mineral within a useful hardness range, but weathering, grain size, coatings, and confusion between a scratch and a powder mark can produce false results. — https://lithomap.app/resources/field-tests/mohs-hardness-test
- Mineral streak test: Streak records the color of a mineral’s powder and can be more consistent than surface color, especially for metallic and iron-bearing minerals. — https://lithomap.app/resources/field-tests/mineral-streak-test
- Cleavage versus fracture: Breakage pattern is often more reliable than color, but one shiny flat surface is not enough: cleavage must repeat with consistent orientation across the same mineral. — https://lithomap.app/resources/field-tests/cleavage-vs-fracture
- Acid reaction test: Acid effervescence is a useful carbonate clue, but chemical handling, coatings, powdered tests, and mixed rocks make it a controlled last-step test rather than a casual first check. — https://lithomap.app/resources/field-tests/acid-reaction-test
- Mineral magnetism test: Magnetic response can quickly separate some iron-bearing minerals, but grain size, intergrowths, weathering, and magnet strength make it a supporting property rather than a complete identification. — https://lithomap.app/resources/field-tests/mineral-magnetism-test
- Specific gravity and density test: Heft is a useful first impression, but a simple hydrostatic measurement provides stronger evidence for unusually dense minerals when porosity, trapped bubbles, and water-sensitive material are controlled. — https://lithomap.app/resources/field-tests/specific-gravity-density-test

Begin with nondestructive observation, use the least destructive useful test, record uncertainty, avoid hazardous or valuable material, and verify legal access and collecting rules with the responsible authority.