A constituent mineral present in small quantity and not taken into account in identifying a rock.
More example sentences
- But zircon is rarely present in large quantities in any one rock, making it what geologists call an accessory mineral: a mineral present in such meager quantities that geologists usually pay it little heed.
- Titanite is a common accessory mineral in metamorphic rocks, especially those with a high Ca / Al ratio such as limestones and calc-silicate rocks.
- Corundum occurs as an accessory mineral in some metamorphic rocks, such as mica schist, gneiss, and crystalline limestone.
Definition of accessory mineral in:
- The British & World English dictionary