Amazonite Identification Guide
How to identify amazonite, the green-to-blue microcline feldspar, by its color, white perthitic streaks, two cleavages, and hardness.
Read the full Amazonite encyclopedia entry →
What Amazonite Looks Like
Amazonite is the vivid green to blue-green variety of microcline, a potassium alkali feldspar (KAlSi3O8). Its color comes from trace lead (and water) in the structure.
- Color: bright green, blue-green, to turquoise-blue, frequently with white streaks or patches (perthitic albite intergrowth) giving a grid-like or gridiron sheen.
- Luster: vitreous, pearly on cleavage faces.
- Transparency: translucent to opaque.
- Habit: blocky prismatic crystals (often in pegmatite pockets, sometimes intergrown with smoky quartz), or massive. The characteristic white streaking is diagnostic.
Step-by-Step Field ID Checklist
- Note the color and white streaks. Green-to-blue with white perthitic lamellae or grid pattern is highly characteristic of amazonite.
- Find two cleavages near 90 degrees. Blocky stepped cleavage confirms feldspar.
- Test hardness. Mohs 6–6.5; scratches glass, scratched by quartz.
- Check for the sheen/schiller. A subtle silvery sheen along cleavage from the intergrowth is common.
- Streak. White (color does not transfer).
- Setting. Often with smoky quartz and other pegmatite minerals.
Key Diagnostic Tests
- Hardness: 6–6.5.
- Cleavage: two directions at ~90 degrees (feldspar).
- Specific gravity: ~2.56–2.58 (light).
- Streak: white.
- Color stability: natural amazonite color can fade somewhat with prolonged strong sunlight/heat.
- Acid/magnetism: none.
Common Look-Alikes and How to Tell Them Apart
- Turquoise: similar blue-green but softer (5–6), with no feldspar cleavage and a waxy luster; turquoise often shows brown/black matrix veining rather than white perthitic streaks.
- Chrysocolla/gem silica: blue-green but chrysocolla is softer and gem silica is harder (quartz, 7, no cleavage). Amazonite's two 90-degree cleavages separate it.
- Green aventurine quartz: harder (7), no cleavage, and shows glittery mica/fuchsite inclusions instead of white feldspar streaks.
- Jade (jadeite/nephrite): tougher, no cleavage flashes, and lacks the perthitic white grid; jade has a smoother greasy luster.
- Dyed howlite/magnesite: dye sits in veins, lacks feldspar cleavage, and is softer.
Where Amazonite Is Found
Amazonite forms in granite pegmatites and some granites. Classic localities include Colorado (USA, the Pikes Peak region, where it grows with smoky quartz), Virginia (USA), Brazil, Madagascar, Russia (Ilmen and Kola), and Ethiopia (a major modern source). Look for blocky green feldspar crystals in pegmatite pockets, often perched on or intergrown with smoky quartz and other K-feldspar.
Frequently asked questions
How can you tell if amazonite is real?
Real amazonite is microcline feldspar: hardness 6–6.5, two cleavages meeting near 90 degrees, a white streak, and green-to-blue color usually broken by white perthitic streaks. Softer waxy blue-green stones are likely turquoise or chrysocolla.
What is the difference between amazonite and turquoise?
Amazonite is a feldspar with blocky right-angle cleavage, hardness 6–6.5, and white perthitic streaking. Turquoise is softer (5–6), has no such cleavage, shows a waxy luster, and typically has brown or black matrix veins.
What gives amazonite its green-blue color?
Trace amounts of lead (with structural water) in the microcline cause the green-to-blue color; it is not from copper as in turquoise.
Amazonite vs aventurine — how are they different?
Amazonite is feldspar with cleavage and white streaks, while green aventurine is quartz (hardness 7, no cleavage) that sparkles from included mica or fuchsite flakes.
Does amazonite fade?
It can fade somewhat under prolonged intense sunlight or heat, so it is best to avoid leaving it in strong sun for long periods.
Amazonite identified by the community
Recent Amazonite specimens identified with Rock Identifier.
