That depends on what it's made of and the quality of the crystal.
100
About 31 grand if its "da bomb bomb"
it depends on the crystal as well as how small the piece is.
You can sell Quartz by the pound ranging from $30-$300 for 1 pound depending on its clarity, clesiness, and shape.
100p
$15
$5 a pound
1 Egyptian pound is $1.67 in American money.
$300.000
10$
10000