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Sodalite Deposits and the Limits of Visual Iden...
Sodalite is a feldspathoid mineral usually sold as blue-and-white rock. Learn how it forms, where deposits occur, and why appearance alone cannot confirm identity or treatment.
Sodalite Deposits and the Limits of Visual Iden...
Sodalite is a feldspathoid mineral usually sold as blue-and-white rock. Learn how it forms, where deposits occur, and why appearance alone cannot confirm identity or treatment.
Why Chatoyancy Fades in Some Tiger's Eye and No...
The chatoyant band in tiger's eye depends on fiber diameter, spacing, alignment, and cutting orientation. Learn why some specimens show a sharp moving line and others a soft sheen.
Why Chatoyancy Fades in Some Tiger's Eye and No...
The chatoyant band in tiger's eye depends on fiber diameter, spacing, alignment, and cutting orientation. Learn why some specimens show a sharp moving line and others a soft sheen.
Selenite Iridescence: Why the Trade Name Says N...
Iridescent selenite is gypsum, but the rainbow effect comes from thin layers and fractures, not the mineral itself. Understand the phenomenon, the terminology, and identification limits.
Selenite Iridescence: Why the Trade Name Says N...
Iridescent selenite is gypsum, but the rainbow effect comes from thin layers and fractures, not the mineral itself. Understand the phenomenon, the terminology, and identification limits.
What Labradorite's Flash Cannot Reveal About It...
Labradorite's labradorescence is caused by internal lamellae, not by body color. Learn why appearance cannot establish mineral species, composition, treatment, or origin in plagioclase feldspar.
What Labradorite's Flash Cannot Reveal About It...
Labradorite's labradorescence is caused by internal lamellae, not by body color. Learn why appearance cannot establish mineral species, composition, treatment, or origin in plagioclase feldspar.
Why Density Reveals How Black Tourmaline Forms
Learn how specific gravity and density in black tourmaline reflect iron-rich schorl composition and reveal its geological formation in pegmatites, veins, and metamorphic rocks.
Why Density Reveals How Black Tourmaline Forms
Learn how specific gravity and density in black tourmaline reflect iron-rich schorl composition and reveal its geological formation in pegmatites, veins, and metamorphic rocks.
What Inclusions in Aquamarine Reveal About Its ...
Aquamarine inclusions record growth conditions, geological setting, and sometimes heat treatment. Learn what growth tubes, zoning, and fluid inclusions can and cannot prove gemologically.
What Inclusions in Aquamarine Reveal About Its ...
Aquamarine inclusions record growth conditions, geological setting, and sometimes heat treatment. Learn what growth tubes, zoning, and fluid inclusions can and cannot prove gemologically.