Amethyst — specimen 0406, photo © NMNHS
Weight: 0.48 ct; size: 5.08 | 4.37 | 3.83 mm; shape: hexagon; colour: light bluish violet; very slightly greyish; clarity: eye clean; cut: excellent; treatment: none.
Very clean specimen; design ‘Hexamixtum S 42-43’, 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.