Calciotantite is an exceptionally rare calcium tantalum oxide mineral that typically occurs as small, tabular crystals within highly fractionated granitic pegmatites. Collectors primarily find this species as micro-crystals associated with other rare tantalum-bearing minerals in complex lithium-cesium-tantalum (LCT) pegmatite systems.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Calciotantite

Hardness: 4
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this calciotantite?

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 calciotantite with a known reference. Calciotantite sits at Mohs 4, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Calciotantite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Calciotantite 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: tabular crystals.

Often found alongside calciotantite

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

All properties

Chemical formula: CaTa₄O₁₁
Mohs hardness: 4
Density: 6.12 g/cm³
Colors: Colorless White Yellow
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $200-1000+ for rare micro specimens

Where rockhounds find calciotantite

Classic worldwide localities

Tanco Mine, Canada
Svinninge, Sweden

Field-hunting tip

Look in granite pegmatites country, the host setting where calciotantite typically forms. If you start seeing albite, microcline, quartz 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 calciotantite?+

Mohs hardness is 4. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, yellow.

Where is calciotantite found?+

Notable localities include Tanco Mine, Canada; Svinninge, Sweden.

How much is calciotantite worth?+

Typical asking prices fall in the range of $200-1000+ for rare micro specimens. Quality, size, and provenance can move individual specimens well outside that range.

What minerals are found with calciotantite?+

Calciotantite commonly co-occurs with Albite, Microcline, Quartz, Muscovite, Tantalite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does calciotantite form in?+

Calciotantite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is calciotantite used for?+

Calciotantite is used in collector.

Find calciotantite on the map

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