Engraving in granite

Is the Onefinity strong enough to engrave in hard rocks such as granite ?

Possibly with the correct bit.

I had very little luck carving stone with cheap chinesium diamond coated bits.

I think it’s a factor of the bits. I’ve used it with normal carbide bits to carve soapstone but very small v-bits (like 15*) lose the tips right away. Pretty sure you’ll need some high quality diamond bits and some lubricating mist - might try denatured alcohol that won’t wreck your wasteboard (assuming you’ve got a traditional MDF wasteboard).