How to identify Bloodstone

To correctly identify Bloodstone (Heliotrope (a variety of Chalcedony, which is a cryptocrystalline quartz)), 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 with distinct red, orange, or brown spots/streaks.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Waxy to vitreous (glassy) when polished, dull to waxy on rough surfaces.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Microcrystalline, very fine-grained, smooth to the touch when polished.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Typically massive, botryoidal, or stalactitic; individual crystals are microscopic and not visible to the naked eye.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None, due to its cryptocrystalline nature.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermally altered volcanic rocks (basalts, andesites), metamorphic rocks, and alluvial deposits.

Key Facts

Hardness

6.5-7 on the Mohs scale

Specific Gravity

2.58-2.64

Crystal System

Trigonal (cryptocrystalline aggregates)

Color

Dark green with red, orange, or brown spots

Luster

Waxy to vitreous

Transparency

Translucent to opaque

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; individual crystals are microscopic.
• Cleavage Type: None
• Fracture Type: Conchoidal to uneven
• Tenacity: Brittle
• Luster Type: Waxy to vitreous

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