Earth Record
Mineralogy and formation
Amazonite quartz specimens pair two minerals that grew together in the same pegmatite cavity. The amazonite component is green microcline feldspar, colored by trace lead and water in the crystal lattice. The quartz grew alongside it as silica-rich fluids cooled below 573°C. Colorado's Pikes Peak batholith produces classic examples where teal amazonite crystals sit on or interlock with clear to smoky quartz points.
The two minerals share space but differ in every structural way: feldspar is triclinic, quartz is trigonal. Their coexistence records the final cooling stages of a granitic melt.
Chemical FormulaKAlSi3O8 (amazonite -- microcline feldspar) + SiO2 (smoky quartz), often with accessory minerals including albite, fluorite, goethite, and occasionally topazCrystal SystemMixedMohs Hardness6.5Specific Gravity2.56--2.58 (amazonite); 2.65 (smoky quartz)LusterVitreous to pearly (amazonite); vitreous (smoky quartz)ColorGreenIMA Statustrade_nameIMA NumberNot Valid (variety of Microcline, pre-IMA) Colorado (USA)BrazilRussia
Telling it apart
Amazonite quartz is commonly mistaken for a single mineral, but it is a composite specimen, green amazonite feldspar growing with clear or milky quartz. The confirming step is hardness contrast and cleavage: quartz scratches amazonite, quartz has no cleavage and conchoidal fracture at Mohs 7, while amazonite is microcline feldspar at Mohs 6 to 6. 5 with two cleavages meeting near 90 degrees.
Genuine pieces show distinct white, clear, or smoky quartz attached to blue green amazonite, not one uniform green mass. The amazonite areas usually look blocky with flat cleavage faces and a pearly sheen on some surfaces, while the quartz areas look glassier and more conchoidal. If a seller markets the whole piece as one rare crystal species, that is wrong. This is an association specimen, and that is the point.
Dyed green quartz and resin composites look too even in color and lack the sharp textural split between feldspar and quartz. Ask which part is which before the practitioner buy. A fair purchase depends on this because composite names confuse beginners, and sloppy labeling turns a normal pegmatite association into fake rarity.
Spotting the real thing
Amazonite quartz is a composite specimen. Verify both components: green amazonite (microcline feldspar, Mohs 6-6. 5, grid-like twinning sometimes visible) and smoky quartz (Mohs 7, conchoidal fracture).
The two minerals should appear naturally intergrown, not glued. Check the contact between them; natural intergrowths show crystal faces growing into each other, not flat adhesive lines.
Cross-referenceMindat ↗