Garnet · Variety of Garnet
Spessartite
Mandarin orange to reddish orange
Orange
Optical characteristics
- Ref. index
- 1.79 – 1.82
- Luster
- Vitreous to adamantine
- Pleochroism
- None None; garnets are singly refractive and isotropic.
- Fluorescence
- Usually inert.
Source localities
Tanzania
Tanzania: Merelani Hills
Major
Major source for tanzanite, garnet, spinel, tourmaline, ruby and fancy sapphires.
Madagascar
Madagascar: Ilakaka / Andranondambo region
Major
Modern major source for sapphire, garnet, beryl, quartz, tourmaline and many collector gems.
Nigeria
Nigeria: Oyo / Ogun / Plateau fields
Major
Important source for tourmaline, sapphire, garnet, beryl and topaz.
Namibia
Namibia: Erongo / Green Dragon area
Notable
Known for demantoid, spessartite and collector minerals.
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…
Instruments used
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