Tanzanite Rough and Dichroism

In this video Steve Moriarty discusses Tanzanite Dichroism. He describes the different colors that can be seen in Tanzanite and how it relates to Dichroism. See a Tanzanite that's not quite completed and still in the cutting stage, still on the cutting machine.

VIDEO TRANSCRIPTION

Now, this is a tanzanite that's still on the dock. We're about halfway through cutting it. We've cut the pavilion, and it's a very good example of dichroism in tanzanite. 

What you're seeing are coming up would be the air, the B axis. In the dichroscope it shows purple and yellow. And the next axis would be the C axis, and its colors in the dichroscope are blue and yellow. The one axis, we're not seeing which is the air, the B axis, and it would be blue and purple in the dichroscope, and that color would be directly down through the table of this stone that's attached directly to the dock.