Oligoclase — specimen 0285, photo © NMNHS

Oligoclase — specimen 0285

Origin

East Africa

Madagascar

Oligoclase — specimen 0285, locality map

Data

Weight: 0.96 ct; size: 6.13 | 6.10 | 4.70 mm; shape: octagon; colour: very light very slightly bluish green; clarity: eye clean; cut: excellent; treatment: none.

Notes

Very clean specimen; design ‘Eight’ [pavilion angle changed to 44.00] by Glenn & Martha Vargas, excellent cut by Tan Pen.

Other specimens

More information from ‘Classification’

Oligoclase

A variety of albite; plagioclase feldspar with an albite:anorthite molar ratio ranging from 90:10 to 70:30.