Paralstonite is a rare barium calcium carbonate mineral that is structurally related to alstonite. It is most famously found in the Illinois-Kentucky fluorspar district, often occurring as sharp, pseudo-hexagonal crystals embedded in or associated with fluorite.

Hardness

4.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareAlstonite-Paralstonite Group family

Paralstonite

Hardness: 4.5
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this paralstonite?

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 paralstonite with a known reference. Paralstonite sits at Mohs 4.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Paralstonite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Paralstonite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white, yellow.
5
Look at form & habit
Crystal system: trigonal. Typical habit: pseudo-hexagonal dipyramidal crystals.

Often confused with

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

How to tell apart: Paralstonite is noticeably harder (Mohs 4.5 vs. 3-3.5).

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Often found alongside paralstonite

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

All properties

Chemical formula: BaCa(CO₃)₂
Mohs hardness: 4.5
Density: 3.62 g/cm³
Colors: Colorless White Yellow
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Pseudo-hexagonal Dipyramidal Crystals
Cleavage: Distinct On {1011}
Fluorescence: Bright White/yellow Under SW UV
Rarity: Rare
Uses: Collector
Host rock: Low-temperature Hydrothermal Veins in Sedimentary Rocks
Typical price: $50-300 per specimen depending on size and quality

Where rockhounds find paralstonite

Classic worldwide localities

Minerva No. 1 Mine, Illinois, USA
Cave-in-Rock, Illinois, USA

Field-hunting tip

Look in low-temperature hydrothermal veins in sedimentary rocks country, the host setting where paralstonite typically forms. If you start seeing fluorite, calcite, quartz in float, you are in the right ground. Field specimens usually show a pseudo-hexagonal dipyramidal crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify paralstonite?+

Mohs hardness is 4.5. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, yellow.

Where is paralstonite found?+

Notable localities include Minerva No. 1 Mine, Illinois, USA; Cave-in-Rock, Illinois, USA.

How much is paralstonite worth?+

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

What rocks look like paralstonite?+

Paralstonite is most often confused with Alstonite, Barytocalcite, Witherite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with paralstonite?+

Paralstonite commonly co-occurs with Fluorite, Calcite, Quartz, Galena, Sphalerite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does paralstonite form in?+

Paralstonite typically forms in low-temperature hydrothermal veins in sedimentary rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is paralstonite used for?+

Paralstonite is used in collector.

Find paralstonite on the map

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