Crystal Structure
Cyclosilicate — Si₆O₁₈ rings stacked; channels along c-axis host trace cations + H₂O.
Elemental Composition (by mass)
| Element | Mass % | Visual |
|---|---|---|
| O Oxygen | 53.58% | |
| Si Silicon | 31.35% | |
| Al Aluminum | 10.04% | |
| Be Beryllium | 5.03% |
Computed from simplified end-member formula. Solid-solution series, water content, and trace substitutions cause real-world variation.
IMA Abbreviation (Whitney-Evans 2010)
Brl
→ Beryl
Pegmatite assemblages
Standard symbol from American Mineralogist (Whitney & Evans, 2010). Used in thin-section labeling, phase diagrams, and IMA-style species records.
Pronunciation
/ˈbɛrəl/
↔ BEH-ril
two syllables (Greek)
Lapidary & Faceting Recommendations
Recommended cut:
step / oval
Also seen:
cushion, emerald
Typical yield:
35% of rough
General beryl group — see species (emerald/aquamarine etc.).
UV Fluorescence
SW (254 nm)
—
none
LW (365 nm)
—
none
Pure beryl inert; Cr/V-bearing emerald may show weak red.
SW = shortwave (germicidal lamp). LW = longwave (blacklight). Response varies with locality, trace impurities, and treatment.
Tenacity
Behavior:
brittle
Under stress:
Conchoidal fracture
Hard but brittle — emerald especially fragile due to "jardin".
Luster
vitreous
Standard glass-like.
Diaphaneity (Transparency)
transparent-to-translucent
Gem-quality transparent.
Magnetism
Category:
diamagnetic
Test result:
Slight repulsion
Be₃Al₂(SiO₃)₆; pure form diamagnetic.
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
2.66–2.92
g/cm³
light
Higher SG in Fe-rich (heliodor) and Cs-rich pegmatitic material.
For comparison: water = 1.00, glass ≈ 2.5, quartz = 2.65, corundum ≈ 4.00, galena ≈ 7.50, gold ≈ 19.3.
Geological Setting
Environment:
pegmatite
Host rock:
granitic pegmatite, mica schist (emerald)
Companions:
Pegmatitic for most varieties; emerald is the exception — forms in metasomatized mica schist.
Characteristic Inclusions
Two-phase / three-phasethree-phase
Pegmatitic beryl commonly hosts multi-phase fluid inclusions.
★ Diagnostic inclusions are characteristic enough to help identify origin or species under 10× loupe.
Care notesStable. Gem-clarity pieces should not be ultrasonic-cleaned (filled inclusions). Full cleaning guide →
Formation eraGranite pegmatite; Brazilian pegmatites Precambrian (Eastern Brazilian Province ~500 Ma).
Cleavage & Fracture
Cleavage:
indistinct 1 indistinct {0001} — basal
Fracture:
conchoidal / uneven
Mostly fractures conchoidally; very poor basal cleavage.
Market availability: Uncommon
Found at major shows and select dealers. Quality varies by locality.
Collector tier: Cabinet Classic
World-class display species — sought after for cabinet collections, well-documented localities, frequent show-piece pieces.
Named varieties — color spectrum
Mohs 7.5–8
Vickers (~) 1650 HV
Knoop (~) 1340 HK
Nickel–Strunz
9.CJ.05Dana
61.01.01.01Geological setting
PegmatiteMetamorphicHydrothermal
Element composition by mass
Formula: Be₃Al₂Si₆O₁₈ · molar mass: 537.49 g/mol
| O | 53.58% | |
| Si | 31.35% | |
| Al | 10.04% | |
| Be | 5.03% |
Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.
GroupBeryl Group
Mohs Hardness
7.5–8
Beryl sits at 7.5–8 on the Mohs scale — very hard; only diamond or corundum scratches it.
Colors:
Streak
White
White
Crystal system
Hexagonal
Hexagonal
Pronunciation/ˈbɛrɪl/
Type localityLimoges region, France (classical)
Discovery First described 1798 by Louis-Nicolas Vauquelin (France)
SilicatesSilicates (Cyclosilicates)
TL;DR · 1 min read
Beryl (Be₃Al₂Si₆O₁₈) is a beryllium aluminum cyclosilicate famous for its gem-variety daughters: aquamarine (blue), emerald (green from Cr/V), morganite (pink from Mn), heliodor (yellow from Fe), and goshenite (colorless). All are the same species — only trace-element coloration differs.
Beryl (Be₃Al₂Si₆O₁₈) is a beryllium aluminum cyclosilicate famous for its gem-variety daughters: aquamarine (blue), emerald (green from Cr/V), morganite (pink from Mn), heliodor (yellow from Fe), and goshenite (colorless). All are the same species — only trace-element coloration differs. Beryl forms in granitic pegmatites, hydrothermal veins, and metamorphic rocks; well-formed hexagonal prisms are the signature crystal habit.
More minerals to explore
Sugilite (舒俱徕石)
Hexagonal
Dravite (镁电气石)
Trigonal
Elbaite (锂电气石)
Trigonal
Dioptase (透视石)
Trigonal
Schorl (黑电气石)
Trigonal
Benitoite (蓝锥矿)
Hexagonal
Varieties of Beryl
Beryl is a parent species — the following named varieties differ in color or chemistry but share the same fundamental mineralogy.
- Aquamarine (u6d77u84ddu5b9du77f3)sky-blue to seawater-blueIron-bearing blue/blue-green beryl variety, named for sea water.
- Emerald (u7956u6bcdu7eff)rich greenChromium- and vanadium-bearing green beryl variety; one of the four cardinal gems.
- Morganite (u6469u6839u77f3)pink to peachManganese-bearing pink to peach beryl variety, named for J.P. Morgan.
- Heliodor (u91d1u7effu67f1u77f3)golden-yellowIron-bearing golden-yellow beryl variety.
- Goshenite (u900fu7effu67f1u77f3)colorlessPure colorless beryl variety, used for facetable gems.
- Red Beryl (u7ea2u7effu67f1u77f3)raspberry-redManganese-rich red beryl variety, extremely rare; almost exclusively from Utah USA.