
1) Oxide mineral
Found on
https://www.crosswordclues.com/clue/rynersonite

Rynersonite (Ca(Ta,Nb)2O6) is an oxide mineral. It crystallizes in the orthorhombic crystal system. It is dull, translucent mineral, fibrous in nature. Usually off-white to pale pink in color. It occurs in granitic pegmatites and was first described for an occurrence in San Diego County, California in 1978. Besides the San Diego, California area, ...
Found on
http://en.wikipedia.org/wiki/Rynersonite
No exact match found.