Simplotite is a rare hydrous calcium vanadate typically found as thin, black to greenish black coatings or small platy crystals in oxidized uranium-vanadium deposits. It is specifically identified by its association with other secondary vanadium minerals in the sandstone of the Colorado Plateau. Due to its softness and rarity, it is primarily sought after by advanced mineral collectors specializing in vanadium species.
Is this simplotite?
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 simplotite with a known reference. Simplotite sits at Mohs 1, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Simplotite leaves a brownish black streak.
- 3Read the lusterHold the specimen under a strong light. Simplotite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, greenish black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, crusts, earthy aggregates.
Often confused with
Simplotite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Corvusite is the harder of the two (Mohs 2.5-3 vs. 1); streak differs, so Simplotite leaves brownish black, Corvusite leaves purplish blue-black; luster reads vitreous on Simplotite and dull on Corvusite.
How to tell apart: Streak differs, so Simplotite leaves brownish black, Hewettite leaves brownish red; luster reads vitreous on Simplotite and silky to adamantine on Hewettite.
Often found alongside simplotite
Minerals reported to co-occur with simplotite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaV₄O₉·5H₂O
- Mohs hardness
- 1
- Density
- 2.8 g/cm³
- Colors
- Streak
- Brownish Black
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals, Crusts, Earthy Aggregates
- Cleavage
- Perfect in One Direction
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Sandstone Hosted Uranium-vanadium Deposits
Where rockhounds find simplotite
Classic worldwide localities
- Colorado Plateau, USA
- Montrose County, Colorado, USA
- San Juan County, Utah, USA
Field-hunting tip
Look in sandstone hosted uranium-vanadium deposits country, the host setting where simplotite typically forms. If you start seeing tyuyamunite, carnotite, hewettite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, earthy aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify simplotite?+
Where is simplotite found?+
Is simplotite safe to handle?+
What rocks look like simplotite?+
What minerals are found with simplotite?+
What kind of rock does simplotite form in?+
What is simplotite used for?+
Find simplotite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
