Basalt
Basalt is a volcanic stone - it forms from the lava that is spewed out of volcanoes when they erupt. The Egyptians used it to make statues.
Egyptian basalt statue
of Cleopatra (not that Cleopatra,
but an earlier one, related to her)
from the Hermitage Museum in Russia
It is a very hard, black stone, and so the Romans used it for roads. People in the ancient world also used basalt for grinding stones, to grind wheat. Basalt (bu-SALT) grinding stones were often shipped to markets all over the Mediterranean, so people could have good grinding stones even where there weren't any volcanoes.
To find out more about basalt, check out this book from Amazon.com or from your library:
Volcanoes, by Peter Francis and Clive Oppenheimer (second edition 2004).
