Skip to main content

Marble's Reagent

Material Specific

Composition

10g CuSO₄, 50ml NH₄OH, 50ml H₂O

Mixed

Method

Immersion

Time

30s

Alternative Names

Marble's Etchant

Tags

coppercopper-alloybrass

Reveals

Grain boundaries, twinning

Typical Results

For copper and brass. Reveals grain boundaries and twins.

Color Effects

Grain boundaries dark, twins visible

Compatible Materials

coppercopper-alloybrass

Incompatible Materials

steelaluminum

Application Method

Method:immersion
Typical Time:30 seconds

Preparation Notes

Dissolve 10g CuSO₄ in 50ml water, then add 50ml NH₄OH.

Application Notes

Immerse sample for 30-60 seconds. Rinse with water.

Troubleshooting

Good for revealing annealing twins in copper.

Storage Notes

Store in glass bottle. Shelf life: several weeks.

Alternative Etchants

  • Ammonium Persulfate
  • CU-PASS-SOL

Similar Etchants

  • Ammonium Persulfate

ASTM References

ASTM E407