Bloodstone - the martyr's gem
Bloodstone, green jasper dotted with bright red spots of iron oxide, was treasured in ancient times and long served as the birthstone for March. This attractive chalcedony quartz is also known as Heliotrope because in ancient times polished stones were described as reflecting the sun: perhaps the appearance of the gem reminded the ancients of the red setting sun reflected in the ocean.
Medieval Christians often used bloodstone to carve scenes of the crucifixion and martyrs, leading it to also be dubbed martyr's stone. The legend of the origin of bloodstone says that it was first formed when some drops of Christ's blood fell and stained some jasper at the foot of the cross. A beautiful example of carved bloodstone with the seal of the German Emperor Rudolf II can be seen at the Louvre museum in Paris.
Even today, finely powdered bloodstone is used as a medicine and aphrodisiac in India. Perhaps that explains why today it is difficult to find fine specimens of bloodstone on the market. Bloodstone is mined in India, Australia, and the United States.