Gemstone Encyclopedia

Why Conch Pearls Show Flame Structure but Not Iridescence

Why Conch Pearls Show Flame Structure but Not I...

Learn why conch pearl flame structure is a fibrous scattering effect, not true iridescence, and what this distinction means for gemological identification.

Why Conch Pearls Show Flame Structure but Not I...

Learn why conch pearl flame structure is a fibrous scattering effect, not true iridescence, and what this distinction means for gemological identification.

What Cultured Pearl Appearance Cannot Reveal About Treatments and Material Identity

What Cultured Pearl Appearance Cannot Reveal Ab...

Cultured pearls can look natural, untreated, and solid while internal structure tells a different story. Learn why appearance cannot identify origin, growth environment, or treatment.

What Cultured Pearl Appearance Cannot Reveal Ab...

Cultured pearls can look natural, untreated, and solid while internal structure tells a different story. Learn why appearance cannot identify origin, growth environment, or treatment.

Matrix Opal and the Limits of Refractive Index Testing in Heterogeneous Gem Materials

Matrix Opal and the Limits of Refractive Index ...

Matrix opal is a composite of opal and host rock. Refractive index, birefringence, and optical character cannot be measured as single values. Learn why and what diagnostic methods work instead.

Matrix Opal and the Limits of Refractive Index ...

Matrix opal is a composite of opal and host rock. Refractive index, birefringence, and optical character cannot be measured as single values. Learn why and what diagnostic methods work instead.

Mother of Pearl: Why Some Shells Show Iridescent Flashes and Others Do Not

Mother of Pearl: Why Some Shells Show Iridescen...

Learn why some mother of pearl shows strong iridescent flashes while other shell linings appear plain, and how nacre structure controls this optical difference.

Mother of Pearl: Why Some Shells Show Iridescen...

Learn why some mother of pearl shows strong iridescent flashes while other shell linings appear plain, and how nacre structure controls this optical difference.

Goshenite, Synthetic Beryl, and the Limits of Visual Identification

Goshenite, Synthetic Beryl, and the Limits of V...

How gemologists distinguish natural goshenite from synthetic beryl and treated beryl using inclusions, trace chemistry, and optical properties rather than visual appearance alone.

Goshenite, Synthetic Beryl, and the Limits of V...

How gemologists distinguish natural goshenite from synthetic beryl and treated beryl using inclusions, trace chemistry, and optical properties rather than visual appearance alone.

Distinguishing Hessonite from Spessartine Garnet: The Role of Specific Gravity and Optical Properties

Distinguishing Hessonite from Spessartine Garne...

Hessonite and spessartine garnets are often confused. Discover how specific gravity, refractive index, and inclusions provide reliable gemological identification.

Distinguishing Hessonite from Spessartine Garne...

Hessonite and spessartine garnets are often confused. Discover how specific gravity, refractive index, and inclusions provide reliable gemological identification.