Chrysoberyl is a hard and durable beryllium aluminate known for its high refractive index and distinct pseudo-hexagonal cyclic twinning. Collectors look for its exceptional hardness, often finding it as water-worn pebbles in alluvial gravels or as sharp, well-formed crystals in pegmatites.
Is this chrysoberyl?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch chrysoberyl with a known reference. Chrysoberyl sits at Mohs 8.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: yellow, yellow-green, brown, green, colorless, blue green, brownish green, gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic, tabular, twinning common.
Often confused with
Chrysoberyl vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside chrysoberyl
Minerals reported to co-occur with chrysoberyl. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- BeAl₂O₄
- Mohs hardness
- 8.5
- Density
- 3.75 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent, may be opaque and chatoyant with oriented inclusions
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic, tabular, twinning common
- Cleavage
- Distinct on {110}, imperfect on {010}, poor on {001}
- Rarity
- Uncommon
- Uses
- Gemstone, Collector
- Host rock
- Characteristic of some granite pegmatites associated with high-grade mica schists or reaction zones in ultramafic rocks; also detrital in placers
Where rockhounds find chrysoberyl
4 mapped spotsClassic worldwide localities
- Golden, Jefferson Co., Colorado, USA
- Topsham, Sagadahoc Co., from Paris, Norway, and Hartford, Oxford Co., Maine, USA
- Faria Lemos, Santa Luzia de Carangola, and Americana, Teófilo Otoni, Minas Gerais
- Campo Formoso, Teixeira de Freitas, and Cachoeira, Bahia
- Maršíkov, Czech Republic
- Izumrudnye mines, Tokovaya River, near Yekaterinburg (Sverdlovsk), and Mursinka, Ural Mountains, Russia
Field-hunting tip
Where it forms: Characteristic of some granite pegmatites associated with high-grade mica schists or reaction zones in ultramafic rocks; also detrital in placers. If you start seeing quartz, muscovite, albite in float, you are in the right ground. Typical habit: prismatic, tabular, twinning common. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Maine, Colorado, Connecticut. Start trip planning there.
Common questions
How do you identify chrysoberyl?+
Where is chrysoberyl found?+
Can I find chrysoberyl in the United States?+
Is chrysoberyl safe to handle?+
What rocks look like chrysoberyl?+
What minerals are found with chrysoberyl?+
What kind of rock does chrysoberyl form in?+
What is chrysoberyl used for?+
Find chrysoberyl on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
