Delrioite is a rare hydrated calcium strontium vanadate found primarily in the oxidized zones of vanadium-uranium deposits. It typically forms as delicate, transparent yellow tabular crystals or crusts coating sandstone surfaces. Due to its scarcity and fragility, it is highly sought after by advanced collectors of secondary vanadium minerals.

Hardness

Mohs

Luster

Vitreous

Streak

Yellow

Transparency

Transparent

mineralrare

Delrioite

Hardness: 2
Luster: Vitreous
Streak: Yellow
Transparency: Transparent

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Is this delrioite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch delrioite with a known reference. Delrioite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Delrioite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Delrioite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, yellowish-green.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular, radiating clusters, crusts.

Often confused with

Delrioite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Streak differs — Delrioite leaves yellow, Sherwoodite leaves light blue.

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Often found alongside delrioite

Minerals reported to co-occur with delrioite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: CaSrV₂O₆(OH)₂·3H₂O
Mohs hardness: 2
Density: 2.8 g/cm³
Colors: Yellow Yellowish-green
Streak: Yellow
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular, Radiating Clusters, Crusts
Cleavage: Distinct On {001}
Rarity: Rare
Uses: Collector
Host rock: Vanadium-uranium-bearing Sedimentary Rocks
Typical price: $50-300 per thumbnail specimen

Where rockhounds find delrioite

Classic worldwide localities

Colorado Plateau, USA
Paradox Valley, Colorado
Montrose County, Colorado

Field-hunting tip

Look in vanadium-uranium-bearing sedimentary rocks country — that is the host setting where delrioite typically forms. If you start seeing pascoite, carnotite, rossite in float, you are in the right ground. Field specimens usually show a tabular, radiating clusters, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify delrioite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is yellow. Common colors include yellow, yellowish-green.

Where is delrioite found?+

Notable localities include Colorado Plateau, USA; Paradox Valley, Colorado; Montrose County, Colorado.

How much is delrioite worth?+

Typical asking prices fall in the range of $50-300 per thumbnail specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is delrioite safe to handle?+

It contains toxic constituents. Contains vanadium which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like delrioite?+

Delrioite is most often confused with Pascoite, Sherwoodite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with delrioite?+

Delrioite commonly co-occurs with Pascoite, Carnotite, Rossite, Metarossite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does delrioite form in?+

Delrioite typically forms in vanadium-uranium-bearing sedimentary rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is delrioite used for?+

Delrioite is used in collector.

Find delrioite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.