Paceite is an exceptionally rare calcium copper acetate mineral discovered in the Pace Pit of Kentucky. It typically forms as small, clear, tabular crystals in association with secondary copper minerals within weathered carbonate rocks.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareAcetate Group family

Paceite

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

No image

Is this paceite?

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 paceite with a known reference. Paceite 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. Paceite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Paceite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals.

Often confused with

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

mineral

Calcite

Mohs 3

How to tell apart: Calcite is the harder of the two (Mohs 3 vs. 2).

Often found alongside paceite

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

All properties

Chemical formula: CaCu(CH₃COO)₄·6H₂O
Mohs hardness: 2
Density: 1.74 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Weathered Limestones Containing Copper-bearing Sulfides
Typical price: $50-300 per specimen

Where rockhounds find paceite

Classic worldwide localities

Pace Pit, Kentucky, USA

Field-hunting tip

Look in weathered limestones containing copper-bearing sulfides country — that is the host setting where paceite typically forms. If you start seeing calcite, cuprite, native copper in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify paceite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white.

Where is paceite found?+

Notable localities include Pace Pit, Kentucky, USA.

How much is paceite worth?+

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

What rocks look like paceite?+

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

What minerals are found with paceite?+

Paceite commonly co-occurs with calcite, cuprite, native copper. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does paceite form in?+

Paceite typically forms in weathered limestones containing copper-bearing sulfides. Working float back to the host body is the standard way to chase a fresh occurrence.

What is paceite used for?+

Paceite is used in collector.

Find paceite on the map

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