My quartz of many colours

[lanfykins]

I gave up and spent last night playing with my rocks.

It is possible that lying on your back on the floor holding some bits of glass and plastic up to the light is not a normal way to spend a Friday evening (or indeed any other). But crystals with two refractive indices are pretty when viewed between crossed polars.

I still find it utterly

Comments

[lanfykins]

I was thinking triclinic, yes.

So... where is the single three-fold axis?