Image: Bloodstone 3 (49036281801)
Description: (~12.6 centimeters across at its widest) Bloodstone is a chert-like rock that is composed of cryptocrystalline quartz. It consists of a mix of deep green and deep red quartz. By itself, deep green cryptocrystalline quartz is called "plasma", and the deep red variety is called "jasper". Bloodstone, or "heliotrope", is plasma with spots or streaks or patches of jasper. I have never in my life seen a bloodstone sample with provenance information. Surprisingly, there is little to no technical geologic literature on bloodstone - at least, none that is available and out in the open.
This specimen has zero information about its locality and geologic context. Many claim that most bloodstone comes from India. If this sample is Indian in origin, it is possibly derived from a fracture fill in Deccan Traps basalt lava flows (= Cretaceous-Tertiary boundary times), and possibly from the Kathiawar Peninsula in western India.
Author: James St. John
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