How to identify Bloodstone

To correctly identify Bloodstone (Heliotrope (Chalcedony variety)), check each of these features in order. Many rocks and minerals look alike, so cross-reference multiple properties before deciding.

Step-by-step identification

1. 1

   Color

   Overall color and any zoning or banding

   Dark green body color with distinct red, reddish-brown, or yellow spots/patches.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Waxy to vitreous.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth when polished, microgranular.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Cryptocrystalline, massive aggregates; individual crystals are microscopic and not visible to the naked eye.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None, exhibits conchoidal fracture.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Found in igneous rocks (especially volcanic), metamorphic rocks, and as pebbles in alluvial deposits. Often associated with hydrothermal veins or altered zones.

Key Facts

Hardness

6.5-7 on Mohs scale

Specific Gravity

2.58-2.64

Crystal System

Trigonal (cryptocrystalline)

Color

Dark green with red, reddish-brown, or yellow spots

Luster

Waxy to vitreous

Transparency

Opaque to slightly translucent

Fracture

Conchoidal to uneven

Cleavage

None

Composition

Silicon dioxide (SiO2) with iron oxide (hematite) and chlorite/hornblende inclusions

Physical characteristics

• Crystal Habit: Massive, cryptocrystalline aggregates; microgranular
• Cleavage Type: None
• Fracture Type: Conchoidal to uneven
• Tenacity: Brittle
• Luster Type: Waxy to vitreous

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