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

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).

Compare →

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 — that is 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.