Leucosphenite is a rare barium-titanium silicate known for its distinct wedge-shaped tabular crystals and strong blue fluorescence under short-wave UV light. It is most famous among collectors for specimens sourced from the alkaline igneous complexes of Mont Saint-Hilaire. Due to its rarity and specific geological occurrence, it is primarily sought by advanced mineral collectors and those interested in exotic pegmatite minerals.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Leucosphenite

Hardness: 6
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this leucosphenite?

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 leucosphenite with a known reference. Leucosphenite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Leucosphenite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Leucosphenite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, yellow, brown, colorless.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals, wedge-shaped.

Often confused with

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

Often found alongside leucosphenite

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

All properties

Chemical formula: Na₄BaTi₂B₂Si₁₀O₃₀
Mohs hardness: 6
Density: 3.0 g/cm³
Colors: White Yellow Brown Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals, Wedge-shaped
Cleavage: Perfect On {001}
Fluorescence: Bright Blue Under SW UV
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Nepheline Syenite Pegmatites
Typical price: $50-500 depending on specimen quality and size

Where rockhounds find leucosphenite

Classic worldwide localities

Mont Saint-Hilaire, Quebec, Canada
Narssârssuk, Greenland
Khibiny Massif, Russia

Field-hunting tip

Look in nepheline syenite pegmatites country, the host setting where leucosphenite typically forms. If you start seeing aegirine, microcline, sodalite in float, you are in the right ground. Field specimens usually show a tabular crystals, wedge-shaped habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify leucosphenite?+

Mohs hardness is 6. It typically shows a vitreous luster. The streak is white. Common colors include white, yellow, brown, colorless.

Where is leucosphenite found?+

Notable localities include Mont Saint-Hilaire, Quebec, Canada; Narssârssuk, Greenland; Khibiny Massif, Russia.

How much is leucosphenite worth?+

Typical asking prices fall in the range of $50-500 depending on specimen quality and size. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like leucosphenite?+

Leucosphenite is most often confused with Barylite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with leucosphenite?+

Leucosphenite commonly co-occurs with Aegirine, Microcline, Sodalite, Nepheline, Catapleiite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does leucosphenite form in?+

Leucosphenite typically forms in nepheline syenite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is leucosphenite used for?+

Leucosphenite is used in collector, scientific research.

Find leucosphenite on the map

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