accessory mineral

noun

, Petrography.

1. a mineral that is present in small amounts in a rock and has no bearing on the classification of the rock, as zircon in granite.

accessory mineral

1. A mineral that is present in a minor amount in rocks and is not considered an essential constituent of the rock.

Example Sentences

It is frequently present as an accessory mineral in sulphide deposits containing ores of gold, copper, silver, lead, and zinc.

From Project Gutenberg