Gemstone Science

Distinguishing Natural Moonstone from Synthetic Feldspar: Building an Evidence Chain

Distinguishing Natural Moonstone from Synthetic...

How gemologists distinguish natural moonstone from synthetic feldspar using microscopy, trace-element chemistry, and structural evidence, and why no single test is definitive.

Distinguishing Natural Moonstone from Synthetic...

How gemologists distinguish natural moonstone from synthetic feldspar using microscopy, trace-element chemistry, and structural evidence, and why no single test is definitive.

When Beryl Loses Its Beryllium: How Alkali Substitution and Channel Chemistry Shape Aquamarine

When Beryl Loses Its Beryllium: How Alkali Subs...

How channel alkalis, unit-cell changes, and trace-element chemistry connect beryl's geological formation to aquamarine's properties and analytical limits.

When Beryl Loses Its Beryllium: How Alkali Subs...

How channel alkalis, unit-cell changes, and trace-element chemistry connect beryl's geological formation to aquamarine's properties and analytical limits.

Opal, Pleochroism, and the Limits of Optical Anisotropy: Why Play-of-Color Is Not a Polarization Effect

Opal, Pleochroism, and the Limits of Optical An...

Is opal pleochroic? Learn why opal's play-of-color is a structural interference effect, not direction-dependent absorption in an anisotropic crystal lattice.

Opal, Pleochroism, and the Limits of Optical An...

Is opal pleochroic? Learn why opal's play-of-color is a structural interference effect, not direction-dependent absorption in an anisotropic crystal lattice.

How Lattice Defects Shape Sapphire Color: Substitution, Charge Compensation, and the Limits of Trace-Element Explanations

How Lattice Defects Shape Sapphire Color: Subst...

How trace elements, oxidation states, charge compensation, and radiation-induced defects produce sapphire color, and why bulk chemical analysis cannot fully explain it.

How Lattice Defects Shape Sapphire Color: Subst...

How trace elements, oxidation states, charge compensation, and radiation-induced defects produce sapphire color, and why bulk chemical analysis cannot fully explain it.

Detecting Thin-Film Coatings on Moissanite: When Two Analytical Methods Disagree

Detecting Thin-Film Coatings on Moissanite: Whe...

Reflected-light microscopy and Raman spectroscopy sample moissanite differently. A thin coating can be visible at the surface yet absent from a bulk-dominated spectrum, so the two methods answer different questions.

Detecting Thin-Film Coatings on Moissanite: Whe...

Reflected-light microscopy and Raman spectroscopy sample moissanite differently. A thin coating can be visible at the surface yet absent from a bulk-dominated spectrum, so the two methods answer different questions.

Vesuvianite Solid Solution: When a Mineral Formula Becomes a Moving Target

Vesuvianite Solid Solution: When a Mineral Form...

How coupled substitution and multiple cation sites make vesuvianite a solid-solution mineral, and why one formula cannot capture its composition, color, or identity.

Vesuvianite Solid Solution: When a Mineral Form...

How coupled substitution and multiple cation sites make vesuvianite a solid-solution mineral, and why one formula cannot capture its composition, color, or identity.