Pyrope

Mg3Al2(SiO4)3

Pyrope is a silicate mineral prized by collectors for its exceptional color range, with several world-class Chinese localities.

Crystal Structure
Cubic garnet — Mg₃Al₂(SiO₄)₃.
Elemental Composition (by mass)
ElementMass %Visual
O Oxygen47.63%
Si Silicon20.90%
Mg Magnesium18.09%
Al Aluminum13.39%
Computed from simplified end-member formula. Solid-solution series, water content, and trace substitutions cause real-world variation.
IMA Abbreviation (Whitney-Evans 2010)
Prp
→ Pyrope
Garnet
Standard symbol from American Mineralogist (Whitney & Evans, 2010). Used in thin-section labeling, phase diagrams, and IMA-style species records.
Pronunciation
/ˈpaɪroʊp/
PYE-rope
Greek "fire-eyed"
Luster
vitreous
Standard vitreous.
Color Cause (Chromophore)
Chromophore:
Fe²⁺ + Cr³⁺
Mechanism:
idiochromatic
Color produced:
red
Fe²⁺ baseline plus Cr³⁺ deepens red. Bohemian pyrope famous.
Diaphaneity (Transparency)
transparent
Mg-Al garnet — gem-grade.
Type Locality
(general) — Bohemia
Described 1803 by Werner
› Browse all type localities
Magnetism
Category:
weakly paramagnetic
Test result:
Weak but detectable
Mg-Fe garnet — usually less magnetic than almandine.
Test with rare-earth magnet (N42 or N52 neodymium). Suspend specimen on thread for sensitive paramagnetic detection. Diamagnetic minerals are weakly repelled (visible only with strong magnets like bismuth).
Specific Gravity
3.65–3.84
g/cm³
medium
Mg-Al garnet; lightest pyralspite garnet.
For comparison: water = 1.00, glass ≈ 2.5, quartz = 2.65, corundum ≈ 4.00, galena ≈ 7.50, gold ≈ 19.3.
Formation eraMantle-derived; >100 km depth. Specimens > 1Ga common from cratonic kimberlites.
Market availability: Uncommon
Found at major shows and select dealers. Quality varies by locality.
Collector tier: Solid Display
Reliable mid-tier display species. Easy to find in well-formed examples; broad locality diversity.
Often found withOlivine · Diopside · Chromite
Mohs 7–7.5
Vickers (~) 1400 HV
Knoop (~) 1100 HK
Geological setting
KimberlitePlacer
Element composition by mass

Formula: Mg₃Al₂(SiO₄)₃ · molar mass: 403.12 g/mol

O 47.63%
Si 20.9%
Mg 18.09%
Al 13.39%

Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.

GroupGarnet Group
Related members: Almandine · Spessartine · Andradite · Grossular · Uvarovite
Mohs Hardness 7–7.5

Pyrope sits at 7–7.5 on the Mohs scale — harder than glass; scratches steel.

Colors:
Streak
White
Crystal system
Isometric (Cubic)
Type localityBohemia, Czech Republic
Discovery First described 1803 by Werner (Bohemia)
SilicatesSilicates (Nesosilicates)
TL;DR · 1 min read
Pyrope (Mg₃Al₂(SiO₄)₃) is the magnesium end-member of the garnet group and completes the pyralspite trio with almandine (Fe) and spessartine (Mn). Its name from Greek "pyropos" (fiery-eyed) reflects the deep wine-red to blood-red color from chromium and iron substitution.

Pyrope (Mg₃Al₂(SiO₄)₃) is the magnesium end-member of the garnet group and completes the pyralspite trio with almandine (Fe) and spessartine (Mn). Its name from Greek “pyropos” (fiery-eyed) reflects the deep wine-red to blood-red color from chromium and iron substitution. Pyrope is famous as the host garnet of diamond-bearing kimberlite pipes, and as Bohemian Garnet — the historic gem of European royal jewelry from 17th-century mines in the modern Czech Republic.

More minerals to explore

Other Members of the Garnet Group

石榴石族