Reinstatement of stibiomicrolite as a valid species

Abstract

The name stibiomicrolite was first used by Quensel & Berggren (1938) to describe a hypothetical primary mineral at the Varuträsk pegmatite in Sweden. The name was later applied to a microlite found as a breakdown product of stibiotantalite at Varuträsk, but Fleischer (1942) discredited stibiomicrolite because of a lack of reliable compositional data. We have re-examined the stibiotantalite ← microlite + antimony assemblage, and our results show that the microlite composition satisfies the specifications for naming new minerals in the pyrochlore group (Hogarth 1977), as Sb constitutes 24.5 to 44.6 at.% of the A-site population, surpassing the required 20% minimum. Our proposal to re-instate the mineral species under its original namne stibiomicrolite has been approved by the International Mineralogical Association.

Key Words:

• Stibiomicrolite
• microlite group
• tantalum
• antimony
• pegmatite
• Sweden