Antimony

Antimony

COLOR

White with a very light creamy shade. Pleochroism is extremely weak. Takes a good polish. Unlike native arsenic, does not tarnish in air.

REFLECTANCE

Quite high. Is surpassed only by native silver and moschellandsbergite. Higher than arsenic and bismuth.

ANISOTROPISM

Rather strong and colored; tints turn characteristic orange-brown and yellow-brown. By comparison, arsenic polarizes in lighter yellow and less orange-colored tints.

TEXTURE

Antimony is consistently found with lamellar twins in several directions. Occurs as equigranular xenomorphic aggregates, sometimes as concentric botryoidal masses with sinuous extinction, encrusting dyscrasite crystals. Often occurs as small grains enclosed in stibnite.

ASSOCIATED MINERALS

Native arsenic, dyscrasite, cobalt-nickel minerals, stibnite, silver minerals.

CRITERIA OF DETERMINATION

The very high reflectance, anisotropism in orange-brown tints, polysynthetic twins are characteristic. Arsenic polarizes in less orange-colored tints and tarnishes rapidly in air. Native silver is isotropic. Dyscrasote polarizes weakly without many shades and has no or few twins. Native bismuth has a more pinkish cream color and polarizes in green tints.

Source

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