How to identify Amazonite, Carnelian, Citrine

To correctly identify Amazonite, Carnelian, Citrine (Amazonite (variety of Microcline Feldspar), Carnelian (variety of Chalcedony), Citrine (variety of 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

   Amazonite: Distinctive blue-green to green. Carnelian: Translucent reddish-orange to brownish-red. Citrine: Transparent yellow to orange-brown.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Amazonite: Vitreous to pearly. Carnelian: Waxy to vitreous. Citrine: Vitreous.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Amazonite: Smooth, often with fine striations. Carnelian: Smooth, often conchoidal fracture surfaces. Citrine: Smooth, glassy.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Amazonite: Typically anhedral to subhedral masses, sometimes prismatic crystals. Carnelian: Cryptocrystalline aggregates, massive. Citrine: Prismatic hexagonal crystals, often in geodes or drusy coatings.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Amazonite: Perfect in two directions at nearly 90 degrees. Carnelian: None (cryptocrystalline). Citrine: None (conchoidal fracture).

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Amazonite: Granitic pegmatites, syenites, and some hydrothermal veins. Carnelian: Volcanic rocks, sedimentary deposits (e.g., geodes, nodules), hydrothermal veins. Citrine: Hydrothermal veins, pegmatites, igneous and metamorphic rocks, often found in geodes.

Key Facts

Hardness

Amazonite: 6-6.5 (Mohs); Carnelian: 6.5-7 (Mohs); Citrine: 7 (Mohs)

Specific Gravity

Amazonite: 2.56-2.58; Carnelian: 2.58-2.64; Citrine: 2.65

Crystal System

Amazonite: Triclinic; Carnelian: Trigonal (cryptocrystalline); Citrine: Trigonal

Color

Amazonite: Blue-green, green; Carnelian: Reddish-orange, brownish-red; Citrine: Yellow, orange-brown

Luster

Amazonite: Vitreous to pearly; Carnelian: Waxy to vitreous; Citrine: Vitreous

Transparency

Amazonite: Translucent to opaque; Carnelian: Translucent; Citrine: Transparent

Fracture

Amazonite: Uneven to conchoidal; Carnelian: Conchoidal; Citrine: Conchoidal

Cleavage

Amazonite: Perfect in two directions at nearly 90 degrees; Carnelian: None; Citrine: None

Composition

Amazonite: Potassium aluminum silicate; Carnelian: Silicon dioxide; Citrine: Silicon dioxide

Physical characteristics

• Crystal Habit: Amazonite: Prismatic, massive; Carnelian: Massive, botryoidal, stalactitic; Citrine: Prismatic, massive, drusy
• Cleavage Type: Amazonite: Perfect {001} and {010}; Carnelian: Not applicable; Citrine: Not applicable
• Fracture Type: Amazonite: Uneven to conchoidal; Carnelian: Conchoidal; Citrine: Conchoidal
• Tenacity: Amazonite: Brittle; Carnelian: Tough; Citrine: Brittle
• Luster Type: Amazonite: Vitreous to pearly; Carnelian: Waxy to vitreous; Citrine: Vitreous

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