Lapis Lazuli translates from the Arabic as 'heaven' or 'sky' stone. This name is easily understood when seen at its best, as an intense and brilliant blue; sublime and pure. The best quality material is a deep, even blue with minimal pyrite inclusions, but many people like the speckles of gold. It is also often characterised by white calcite inclusions, which can also help to distinguish dyed from natural material. The material that I have that is matte finish is not treated, but bear in mind that lapis is a soft and porous stone, and the waxes used to polish will be absorbed by the stone and may be felt on the surface.