Bloodstone.

Bloodstone is a variety of chalcedony, technically a green jasper coloured by chlorite or hornblende inclusions and spotted with red iron oxide. The older name heliotrope (from the Greek for sun-turning) comes from a classical belief that the stone changed the colour of reflected sunlight when placed in water. The English name simply names the obvious: green ground, red blood-flecks.

The stone has a particularly dense Christian iconographic history. Medieval European tradition held that bloodstone formed when drops of Christ's blood fell on green jasper at the foot of the cross, and the gem appears repeatedly in reliquaries and devotional carvings of the period. Roman soldiers had carried it earlier as an amulet for endurance and the staunching of wounds, and the two traditions merged in the medieval reading of the stone as one for hard service.

In modern crystal practice bloodstone sits with the root chakra and reaches into the heart through the green ground. It is the piece people keep through long demanding seasons: caregiving, recovery, work that outlasts the energy you started it with. A tumbled piece in the pocket is the most common form. The hardness of seven and the lack of fragile cleavage make it tolerant of the daily handling that this kind of carry implies. Bloodstone is also one of the alternative March birthstones, particularly in older birthstone lists.