Synthetic calcium silicate

[strobes]

What do you think? I never seen this material before.
Max operating temp 650C (1200F) Is it good for insulation under hearth?

Specification http://www.iig-llc.com/pdfs/IIG-300-Thermo-12-Gold.pdf
MSDS http://www.glasscellisofab.com/sheet...Insulation.pdf