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Rare Mineral

Benitoite

Blue barium titanium silicate

Blue
Optical properties

Optical characteristics

Ref. index
1.757 – 1.804
Luster
Vitreous
Pleochroism
Variable Variable depending on transparency, orientation, and variety.
Fluorescence
Intense blue-white under SW UV — one of the strongest fluorescences of any gemstone and a key diagnostic feature; inert under LW UV
Origins

Source localities

United States USA: San Benito County / Dallas Gem Mine
Premium ★ Top Source

Known for benitoite, tourmaline and collector minerals.

100% est. supply
Inclusions

Inclusions & features

Crystals Crystal Inclusions Under 10x loupe: solid, well-formed mineral crystals trapped inside the host gem. They may… Fractures Feathers and Fractures Under 10x loupe: irregular internal surfaces that catch light and appear bright, wing-like, or… Fractures Fingerprint Inclusions Under 10x loupe: curved or wavy lines of tiny dots forming patterns that look… Clouds Pinpoint Clouds Under 10x loupe: concentrations of extremely tiny bright dots that individually are too small… Multiphase Two-Phase Inclusions Under 10x loupe: a transparent irregular cavity containing both a liquid phase and a…
Identification

Instruments used

Dichroscope Reveals pleochroism, instantly eliminates singly-refractive stones Immersion Microscope See every internal detail clearly, the professional standard 10x Loupe Your most-used instrument, start every examination here Polariscope Determines single vs. double refraction, quick and conclusive Refractometer Measures refractive index, the backbone of gem identification UV Lamp, Long Wave and Short Wave Fluorescence exposes treatments, synthetics, and origin