.
From the ancient kingdom of Babylon to ancient Greece, this stone was regarded as highly magical. The Greeks called it "Heliotrope" ("Helio" meaning sun and "trope" meaning to to turn) because this one meaningful stone in particular was often polished, and reflected light back to the sky. According to Pliny the Elder, the very first magicians wore this stone to become invisible. Some even believed it had the power to keep its wearers young and vigorous -forever-.
.
Why? Because the typical bloodstone is a dark green jasper that is covered by blood red hematite inclusions. It looks like somebody has gone and bled all over the rock. There are other varieties (shown here), and because of its long and CONTINUING history in mysticism, it is hard to find "typical" specimens anymore (more on that later).
.
Early Gnostics adopted this stone as a bringer of vitality. Early Christians later adopted this stone, and believed that blood splatters came from Christ on the crucifix (and would carve out crucifixes onto the bloodstone, renaming it "martyr stone").
.
The Romans, who liked amalgamating ideas from everyone, believed this a stone of good luck and vitality, and athletes wore it as a talisman in games.
.
Nowadays, some cultures still strongly believe that this stone is mystically tied to blood, health, and vigor, so many of the finest pieces are crushed and drunk as an aphrodisiac (i.e. nature's Viagra). It's also used as a talisman to ward off difficult periods. Ya know, blood stuff!