Amethyst — specimen 0085, photo © NMNHS
Uruguay, Artigas Department
Weight: 0.89 ct; size: 6.53 | 6.52 | 4.23 mm; shape: round; colour: medium violetish blue; very slightly greyish; clarity: eye clean; cut: excellent; treatment: none.
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.