Heliotrope is a mineral that is mostly green with random spots of red. These red spots look like little drops of blood. Because of this, Heliotrope is frequently referred to as the bloodstone. Heliotrope is a form of quartz called Chalcedony.
Chalcedony is a catch all term that includes many well known varieties of cryptocrystalline quartz gemstones. They are found in all 50 States, in many colors and color combinations, and in sedimentary, igneous, and metamorphic rocks. Chalcedony includes carnelian, sard, plasma, prase, bloodstone, onyx, sardonyx, chrysoprase, thundereggs, agate, flint, chert, jasper, petrified wood, and petrified dinosaur bone just to name a few of the better known varieties. (Credit: U.S. Geological Survey)