Natural Blue Chalcedony
Chalcedony is a microcrystalline variety of quartz. This means its crystals are too small to be seen with the naked eye.
In its purest form chalcedony is white but impurities of other minerals cause a wide variety of colours.
Although blue tends to be known as chalcedony, many other colours have their own name. When chalcedony occurs with bands it's known as agate. The apple green variety is chrysoprase, the reddish orange stone is carnelian.
This blue chalcedony stone comes from Africa. It has a smooth texture, slightly waxy lustre and is highly translucent mostly around the edge.