Algondite

Aguilarite

COLOR

Creamy white. Takes a good polish with a few scratches.

REFLECTANCE

Very high, almost metallic. Definitely higher than demeykite which is greenish grey at its contact. Cleraly lower than native copper or silver.

ANISOTROPISM

Rather weak but distinct. No striking color effect observed: yellow-grey to blue-grey and brownish. Tints are brighter under slightly uncrossed Nicole, blue to light brown-yellow and brown.

TEXTURE

As domeykite, the mineral forms incrustations but does not develop idiomorphically.

ASSOCIATED MINERALS

Domeykite (alpha and beta), native copper, cuprite.

CRITERIA OF DETERMINATION

Algodonite differs from native silver by its distinctly lower reflectance and its anisotropy. Also takes a better polish. Differs from arsenic and native antimony by its weaker anisotropy and better polish. Its association with native copper and domeykite is characteristic. Compared to demykite, its reflectance is higher and domeykite (at least the most common , alpha-domeykiste) is isotropic. Strongly resembles dyscrasite, but the latter does not take as good a polish because of its softness. On the other hand, the mineral association aids in determination.

Source

ATLAS OF ORE MINERALS (P. Picot and Z. Johan)