Gemstone Encyclopedia

Why Some Amazonite Is Transparent and Most Is Opaque

Why Some Amazonite Is Transparent and Most Is O...

Amazonite transparency varies from clear to opaque due to exsolution, twinning, and alteration. Learn how growth structures control light scattering in microcline.

Why Some Amazonite Is Transparent and Most Is O...

Amazonite transparency varies from clear to opaque due to exsolution, twinning, and alteration. Learn how growth structures control light scattering in microcline.

Fluorite Inclusions and the Geological Story They Record

Fluorite Inclusions and the Geological Story Th...

Fluorite inclusions record growth conditions and help explain why gem-quality material is uncommon. Learn what fluid inclusions, mineral phases, and growth zoning can and cannot reveal.

Fluorite Inclusions and the Geological Story Th...

Fluorite inclusions record growth conditions and help explain why gem-quality material is uncommon. Learn what fluid inclusions, mineral phases, and growth zoning can and cannot reveal.

Pink Tourmaline Luminescence: Why Fluorescence and Phosphorescence Do Not Prove a Stone Is Untreated

Pink Tourmaline Luminescence: Why Fluorescence ...

Why pink tourmaline glows under UV, what causes fluorescence and phosphorescence, and why luminescence cannot prove a stone is untreated.

Pink Tourmaline Luminescence: Why Fluorescence ...

Why pink tourmaline glows under UV, what causes fluorescence and phosphorescence, and why luminescence cannot prove a stone is untreated.

Why Yellow Sapphire Is Sometimes Found Far From Its Source Rock

Why Yellow Sapphire Is Sometimes Found Far From...

Why yellow sapphire is found both in host rock and in distant gravels. Learn how primary and secondary occurrence differ and what the distinction does and does not reveal about...

Why Yellow Sapphire Is Sometimes Found Far From...

Why yellow sapphire is found both in host rock and in distant gravels. Learn how primary and secondary occurrence differ and what the distinction does and does not reveal about...

Why Kyanite Is Sometimes Cut as a Cabochon: Directional Hardness and the Limits of Faceting

Why Kyanite Is Sometimes Cut as a Cabochon: Dir...

Kyanite has directional hardness and prominent cleavage, making cabochon cutting useful for some specimens and risky faceting. Learn the gemological reasons and limits.

Why Kyanite Is Sometimes Cut as a Cabochon: Dir...

Kyanite has directional hardness and prominent cleavage, making cabochon cutting useful for some specimens and risky faceting. Learn the gemological reasons and limits.

Zircon and Synthetic Zirconia: Why Crystal Structure Separates Two Lookalike Materials

Zircon and Synthetic Zirconia: Why Crystal Stru...

How tetragonal zircon and cubic zirconia differ in crystal structure, birefringence, refractive index, specific gravity, and internal features, and why those distinctions matter in gem identification.

Zircon and Synthetic Zirconia: Why Crystal Stru...

How tetragonal zircon and cubic zirconia differ in crystal structure, birefringence, refractive index, specific gravity, and internal features, and why those distinctions matter in gem identification.