Amethyst — specimen 0169, photo © NMNHS
Weight: 1.51 ct; size: 7.91 | 7.83 | 4.93 mm; shape: octagon; colour: very light bluish violet; clarity: eye clean; cut: excellent; treatment: none.
Very clean specimen; design ‘Octaordinarium’, excellent cut by Tan Pen.
More information from ‘Classification’
A violet variety of quartz. The colour is caused by iron impurities in the 10s to 100s parts per million range.