Dissakisite-(La) is a rare lanthanum-dominant member of the epidote group, often occurring as small, dark, prismatic crystals in metamorphic environments. It is visually indistinguishable from other allanite-group minerals in the field and typically requires chemical analysis for definitive identification. Collectors often seek it out for its significance as a rare earth element-bearing mineral species.

Hardness

6-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareEpidote Group family

Dissakisite-(La)

Hardness: 6-7
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this dissakisite-(la)?

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 dissakisite-(la) with a known reference. Dissakisite-(La) sits at Mohs 6-7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Dissakisite-(La) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Dissakisite-(La) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: black, brown, dark brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals.

Often confused with

Dissakisite-(La) vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Streak differs — Dissakisite-(La) leaves white, Allanite-(Ce) leaves greyish-white; luster reads vitreous on Dissakisite-(La) and submetallic on Allanite-(Ce).

Often found alongside dissakisite-(la)

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

All properties

Chemical formula: CaLaAl₂Fe²⁺(Si₂O₇)(SiO₄)O(OH)
Mohs hardness: 6-7
Density: 3.5-3.6 g/cm³
Colors: Black Brown Dark Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals
Cleavage: Good in One Direction
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Metamorphic Rocks
Typical price: $50-500 depending on crystal quality and size

Where rockhounds find dissakisite-(la)

Classic worldwide localities

Japan
Norway
Italy
United States

Field-hunting tip

Look in metamorphic rocks country — that is the host setting where dissakisite-(la) typically forms. If you start seeing quartz, feldspar, garnet in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify dissakisite-(la)?+

Mohs hardness is 6-7. It typically shows a vitreous luster. The streak is white. Common colors include black, brown, dark brown.

Where is dissakisite-(la) found?+

Notable localities include Japan; Norway; Italy; United States.

How much is dissakisite-(la) worth?+

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

What rocks look like dissakisite-(la)?+

Dissakisite-(La) is most often confused with Epidote, Allanite-(Ce), Clinozoisite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with dissakisite-(la)?+

Dissakisite-(La) commonly co-occurs with Quartz, Feldspar, Garnet, Diopside. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does dissakisite-(la) form in?+

Dissakisite-(La) typically forms in metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is dissakisite-(la) used for?+

Dissakisite-(La) is used in collector, scientific research.

Find dissakisite-(la) on the map

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