Hoelite is an extremely rare organic mineral composed of anthraquinone. It is typically found forming as a sublimate on the surface of burning coal seams, often appearing as delicate, needle-like yellow crystals.
Is this hoelite?
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 hoelite with a known reference. Hoelite sits at Mohs 1-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: light yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: resinous.
- 4Match the color rangeCompare against the expected color range: yellow, yellow green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular needles, thin plates.
Often confused with
Hoelite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside hoelite
Minerals reported to co-occur with hoelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- C₁₄H₈O₂
- Mohs hardness
- 1-2
- Density
- 1.42 g/cm³
- Colors
- Streak
- Light yellow
- Luster
- Resinous
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular needles, thin plates
- Cleavage
- Good
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Very rare, in crusts around the surface vents of a burning coal deposit
Where rockhounds find hoelite
Classic worldwide localities
- Mt. Pyramide, Spitsbergen, Norway
Field-hunting tip
Where it forms: Very rare, in crusts around the surface vents of a burning coal deposit. If you start seeing sal ammoniac, sulfur in float, you are in the right ground. Typical habit: acicular needles, thin plates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hoelite?+
Where is hoelite found?+
What rocks look like hoelite?+
What minerals are found with hoelite?+
What kind of rock does hoelite form in?+
What is hoelite used for?+
Find hoelite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
