Working with such a gorgeous and expensive stone naturally instills ... right methods and using suitable tools. In theory, ...

Lavas include igneous rocks like basalt and granite. Chert is a subgroup ... all three of these families of stone. Instead, the sharpest, finest cutting tools were made of delicate, but fine ...

When monkeys in Thailand use stones as hammers and anvils to help them crack open nuts, they often accidentally create sharp flakes of rock that look like the stone cutting tools made by early humans.

She notes that the manufacture of sharp cutting tools made of stone, which could date as far back to 3.3 million years ago, has long been seen as a key technological innovation in human history ...