How To Clean Rocks

Household Products That Can Be Used As Rock Cleaners

by Betsy Martin
Safety: Always use plastic containers, rubber or nitrile gloves, eye protection, good ventilation, and great care when handling these products.
1. Zud or Barkeeper’s Friend cleansers (contains oxalic acid) – Warm or hot solutions will remove iron stains and are helpful with clay deposits. These cleaners can be used with a toothbrush on sturdy surfaces.
2. Toilet Cleaner (the hydrochloric acid type) dissolves calcite rapidly. After treating anything with an acid, rinse very carefully and soak in ample fresh or distilled water for a while to leach out any acid remaining in crystal seams and fractures. You can then follow up with a final soak in dilute Windex to neutralize remaining traces of acid.
3. Lime Away (dilute hydrochloric acid) dissolves calcite more slowly. Rinse as you would for other acid treatments (see above).
4. Calgon – Dissolve this powdered water softener in water. Use for clay removal.
5. Vinegar (Acetic acid), soda water, colas (carbonic and phosphoric acids) – Will slowly etch out very delicate fossils in limestone. Rinse as you would for other acids (see above)
6. Iron Out (iron stain and clay remover) – Mix with warm water and use with good ventilation. It will lose strength if stored. Rinse with plain water.
7. Bleach – Dilute solutions of bleach can remove organic deposits and disinfect minerals collected in areas used by livestock. Rinse with plain water.
8. Hydrogen peroxide – Use to remove manganese stains. Rinse with plain water.
9. Citric acid – Use to remove manganese stains. Rinse as above for acids.
10. Windex (with ammonia) – A good clay deposit remover and final surface cleanup. Works well in ultrasonic cleaners. Rinse with plain water.
11. Distilled Water – Use to clean sensitive species and as a final soak after acid treatment.

Removing Thin Coatings:
On moderately hard minerals – use toothpaste (a feldspar abrasive) and a toothbrush.
On hard minerals – use toothbrush with pumice powder and water.
On calcite (including bruised places) – quickly dip in vinegar or Lime Away and rinse thoroughly. Repeat. Soak in plain water afterwards to leach any acid from cracks.

The following tools can be used for cleaning minerals and tools:
Toothpicks, seam ripper, bamboo sticks, sewing needles in a pin vise, old dental tools, old toothbrushes, periodontal brushes, canned air, Exacto knife, single edge razor blades, cheap small stiff bristle brushes.
Source: The Gemrock, 06/2015