I was wondering if anyone had a good supplier for calibrated cabs
If you're ok using a UK supplier I can recommend KernowCraft
(kernowcraft.com). I've ordered a fair amount of stuff from them, all
"semi-precious" cabs, and have been quite satisfied.
They carry precious and semi-precious stones, they've got a wide
selection and a lot of their items have an "order 10, get 2 free"
I should mention though that their website is a bit odd. The
navigation is a little klunky and the online ordering process takes a
bit of getting used to (tip: write down what you're ordering because
the invoice at the end only shows their stock numbers, not the
description of the individual items). It's no problem once you get
the hang of it.