Physical performance, the commercial grade we hold, and how a matched run is approved before cutting. This is material quarried in Paraiba and sold on the market as Amazonite Quartzite — a different stone from green feldspar amazonite, and a different stone again from Amazon Green Quartzite.
The library for this stone is being assembled. Send us the size, the location and the colour you are chasing and we will send the relevant documents, and say so plainly if this material will not suit the job.