Don't buy unless you can test the actual slab he is trying to sell you. Refusing to give you a sample until after you buy is unacceptable, especially since he won't guarantee that it's quartzite. You can scratch test pretty easily in the yard but you need a sample to test for etching.

I believe Bianca rhino is actually a marble, not a quartzite. It often goes by the name Mystery White. I only know this because my builder referred me to a stone yard and set up the appointment with the owner. I asked him about Mystery White because a friend of mine recently installed it and told me it was a quartzite. However, the gentleman I met with explained that they are generally the same stone. He imports his from Italy. He said that one thing that causes the confusion is that it has more calcite (I think he said calcite....), which makes it similar to Danby. It should have some definite crystalline deposits. Anyway, I hope this helps!

Why would you go along with buy first, test later? At least do the bottle scratch test.

How did the install turn out for you? How’s the durability and experience? Thanks!