Robatoy wrote: ...
The diamond cleaves, not along a "fissure" but along the underlying crystal facets or planes.
Granite is not a ductile material even as compared to cast iron. It has excellent compressive strength, thermal stability, doesn't rust, etc., ... _BUT_ it doesn't have any significant bending resistance and is far more likely to fracture under a moderate impact than cast iron.
The two materials are so differing in their properties it's unlikely you can even find equivalent measured values for them -- there's no essentially no such thing as "ultimate strength" or "yield strength" for stone as well as a measured Young's modulus.
I've no real idea how well these new tops will hold up in normal use but the disadvantages still seem to have much going against as the pluses have going for them to me. Time will tell, I suppose. If they're really a great thing, they'll take over; otherwise it'll just be a relatively short-lived fad. (The latter would be my guess at the moment)
--