Gold

De Dictionnaire geolien
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Gold


COLOR

Golden yellow. Like most metals, takes a poor polish. Scratches are difficult to avoid. Argentiferous varieties (electrum) are slightly lighter and less yellow.

REFLECTANCE

Extremely high, like most native metals.

ANISOTROPISM

Isotropic but it never becomes completely dark, and a greenish shade is often observed.

TEXTURE

Gold often occurs as inclusions in arsenopyrite, stibnite, cobaltite, ullmannite, or associated with tetradymite and native bismuth. When enclosed within arsenopyrite, it is often in contact with residual inclusions of löllingite.

ASSOCIATED MINERALS

Arsenopyrite, stibnite, cobaltite, all the tellurides.

CRITERIA OF DETERMINATION

The golden yellow colord, extremely high reflectance and poor polish prevent misidentification. Chalcopyrite is much less reflective and appears greenish grey against gold. Copper is redder. Bismuth is far less yellow, more creamy, less reflective and anisotropic. Native silver is whiter.

Source

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