chalcedony:

Parent stone for agate, bloodstone, carnelian, chrysoprase, flint, jasper, onyx, sard, sardonyx

Color ranges from yellow to green to black / can be striped or banded

Mohs hardness : 6.5 - 7

Said to increase physical energy / fosters maternal instinct / banishes fear, depression, sadness

Birthstones for February, March, May, July, August / Zodiac stones for Aries, Leo, Capricorn and Aquarius