Asbestos hearth?

[Theonion]

So I put LVP over my beat up wood floors up to the heath pad. I would like to put a layer of tile over the hearth to even out the height, as the hearth is now depressed below the level of the lvp.
I contacted a tile installer and he said he will need to grind the surface of the hearth so the thinset will adhere.
The only problem is that I'm concerned the hearth might be asbestos or contain asbestos. It looks like brick but it's very smooth. My house was built in 1945 and I have old asbestos cieling tiles, asbestos containing insulation, some old floor tiles and linoleum that were asbestos. I've been careful to cover all of it up.
I'll attach a picture and maybe some of you will be able to identify it

 

[Ctwoodtick]

How much of a height difference is there?
What does stove manual say regarding hearth requirements ( ember only or do they give a specific r value that is needed)?

 

[Theonion]

The hearth is now about 1cm depressed from the vynyl plank. The requirements are 20" from front to non combustible, I'm currently at 16" to the vynyl plank. The plank is rated to 155 degrees, it hasn't gotten over 120 but my plan is to install the tile over the current hearth and then put a stoveboard in front of the stove on top of the vynyl.
I've found some pics of asbestos flooring and mine looks very similar to a couple I found, just the color is different.
Does anyone know if thinset will bond to asbestos tile?

 

[Ctwoodtick]

Sorry to sound like I’m asking the same question twice- but just want to make sure you are aware of the specific hearth protection requirement ( which includes what the stove itself is sitting on). Based on your reply I wasn’t 100% sure.
Does your stove manual state that only a non combustible hearth is needed or does it specify the R value needed?
We have all different levels of knowledge on this forum so I’d rather be sure you are totally clear on this issue than assume wrong and you end up with an issue.
If in fact the stove calls only for non combustible surface, I agree that grinding out suspect tile should be a last resort (and done with appropriate care). Tough for anyone here to know what exact tile you have there. You may have a better idea but at the end of the day, it’s tough to totally know what you may have there. If you felt confident that the thinset would bond well but wanted to be more confident, maybe try putting a tile or 2 in back of the stove in an inconspicuous place to test it out and see if it works? Not sure if you have that as an option.

 

[Supersurvey]

I have seen subway tile that contains lead. Not an expert but thinset and wire mesh should work.

 

[begreen]

If there is an 1" of clearance above the insert I think I would build a custom hearth pad that went under the insert and extended out as far as required, plus a few inches. That would provide continuous protection without a seam. I would make the pad out of 2 layers of 1/2" cement board with a tile or metal covering.