>>19182697>mahoganyFairly light as far as woods are concerned. ... , mahogany is not heavy, so light it even floats!
Lignum vitae is the wood you're looking for, dalbergia melanoxylon would be even heaver but not available on that continent. (and not as interesting mechanically)
But in general geopolymere stuff makes more sense as old stories about dissolving and re-hardening rock are present in the region.