Check out "hearth boards" online, I think they may be exactly what you are looking for.
MUCH cheaper than "hearth pads" and MUCH more subtle looks-wise. Thinner, lighter as well.
I am a wood stove novice, just bought a wood stove and was exploring floor protection (hearth) options, googling "hearth mats" and "hearth pads" and reading threads on discussion boards and not getting ANYTHING close to what I wanted...a minimalist black, thin, pad sized exactly right per my manufacturer's specs (36x36).
I could SEE the exact type of hearth I wanted on Jotul's website and a couple of other wood stove manufacturer's websites. I just couldn't FIND such products by searching "hearth pads" and "hearth mats".
I'm not even sure how but I totally stumbled across "hearth boards" made by Hy-C Company from St. Louis and they are EXACTLY what I was looking for. Steel covered mineral board.
This company needs to re-name their product or something to catch search terms from novices like me because I was on the verge of giving up and building my own "hearth pad" out of plywood and wonderboard and tile, etc. and I was NOT HAPPY about it.
Also the experts on this site should direct know-nothings like me to "hearth boards" right away instead of going into all of the mind-numbing details of building your own "hearth pad" and all the R values and K values, etc.
I called my local stove supplier once I discovered the Hy-C "hearth boards" online and he said that they are PERFECTLY appropriate for my stove (which has a BOTTOM HEAT SHIELD so it doesn't need a ton of R value floor protection).
WHAT A RELIEF! I am juggling enough projects already without adding the "hearth pad" project