most of them are opaque but when you shine the light on them they reflect back. I have found a black golden star which I cannot see through but hold to the sun and it reflects gold strongly, the reflection almost seems to jump off the stone
Cut this stone at chrissy cut the shiny bronzy face as the top,heard a bit about stars ,but I can't see a star so I did not finish the polishing of the stone .Do you gus think the star would have shined up better if highly polished??
What you have there mate is hexagonal crystal growth and this never cabs into a star. Stars are usually devoid of growth rings, and generally of a consistent sheen and colour on the surface. Crystal structures like the one you have can make some great pendants.
Worth putting a good polish on it mate, as the crystal structure becomes highlighted and the blue more vivid. Can make some good jewelery with those stones, and no two ever look alike which gives them sort after uniqueness.