Pyrope Garnet
Last updated: April 2026
Known for its fiery red color, pyrope is a member of the garnet group.
Pyrope Garnet has a specific gravity of 3.78 and a refractive index of 1.730–1.760, with a Mohs hardness of 7.0–7.5. It is singly refractive.
Physical & Optical Properties
Measured with a polariscope, a refractometer, a hydrostatic balance, a Chelsea filter, a UV torch, a loupe, a darkfield loupe and a spectroscope — step-by-step for each.
Through the refractometer
Drawn from the refractive index above, on a 1.40–1.81 scale. How to take this reading.
Related: Garnet Varieties
Key Differentiators
- Blood-red color
- Often very clean
- Lower RI than other red garnets
Common Simulants
- Almandine garnet: Very similar; distinguish by RI (almandine ~1.790 vs pyrope ~1.746) and absorption spectrum (almandine shows iron bands).
- Ruby: Ruby: doubly refractive uniaxial negative; strong red fluorescence; Chelsea filter strongly red; RI 1.762–1.770.
- Red Spinel: Spinel: isotropic like garnet but RI ~1.718 vs pyrope ~1.746; different absorption spectrum.
- Red Glass: Isotropic; gas bubbles or swirl marks under loupe; conchoidal fracture; SG varies but no garnet inclusions.
Commonly Confused With
Commonly confused with: Almandine Garnet, Ruby, Spinel, Glass.
Related Comparisons
Measurement Guides
Identifying a pyrope garnet? Loupewise walks through these tests in order — RI, SG, fluorescence, and more.
Try Loupewise Free →Studying for the GIA, FGA, or FEEG practical? Pyrope Garnet is one of the 132 species in Loupewise’s drill and exam pool — practice identifying it from its measured properties under timed exam conditions.
Practice exams →