No - Stone isn't flammable...
...however severe differences in temperature can cause fracturing due to thermal stress.

And some sealers are flammable - so if your stone counters have a sealer applied, that could cause burn marks from hot pots.

In a kitchen environment, you would either need to be extremely careless (and place yourself in a dangerous situation) or purposely attempt to scorch granite using the tip of a torch.

No, Most granites are silica type rocks and melt at above 1200 degrees and I agree with the last person the extreme heat could cause the granite to crack especially granites with a high concentration of quartz.

I have 3cm granite counters, Solaria, and I'm pretty sure it has a high quartz content. I put things on it all the time right out of the oven. No problem. Before this house I had golden oak granite, same thing. No problem with heat. Hot pans and casseroles all the time. I never use trivets.