Seidozerite is a rare zirconium-rich silicate mineral primarily found in agpaitic alkaline igneous rocks. It typically occurs as flattened, tabular crystals or lamellar aggregates with a distinct brownish-yellow hue and vitreous luster.
Is this seidozerite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch seidozerite with a known reference. Seidozerite sits at Mohs 4-5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow-brown.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: brownish red, reddish yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: radial.
Often confused with
Seidozerite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Seidozerite is noticeably harder (Mohs 4-5 vs. 2-3); streak differs, so Seidozerite leaves yellow-brown, Lamprophyllite leaves pale yellow, may have an orange tint; luster reads vitreous on Seidozerite and submetallic on cleavages on Lamprophyllite.
How to tell apart: Baotite is the harder of the two (Mohs 6 vs. 4-5); streak differs, so Seidozerite leaves yellow-brown, Baotite leaves white; luster reads vitreous on Seidozerite and nearly semimetallic to vitreous on Baotite.
Often found alongside seidozerite
Minerals reported to co-occur with seidozerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₄MnTi₂Zr₂Si₄O₁₇(O,F)₂
- Mohs hardness
- 4-5
- Density
- 3.472 g/cm³
- Streak
- Yellow-brown
- Luster
- Vitreous
- Transparency
- Opaque, translucent in thin fragments
- Crystal system
- Monoclinic
- Crystal habit
- Radial
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In thin veins in nepheline syenite pegmatites in a differentiated alkalic massif (Lovozero massif, Russia)
Where rockhounds find seidozerite
Classic worldwide localities
- Lovozero massif, near the Muruai and Uel'kuai Rivers, Seidozero region, Kola Peninsula, and in the Burpala massif, 120 km north of Lake Baikal, eastern Siberia, Russia
- Val Giuv, Graübunden, Switzerland
Field-hunting tip
Where it forms: In thin veins in nepheline syenite pegmatites in a differentiated alkalic massif (Lovozero massif, Russia). If you start seeing microcline, aegirine, nepheline in float, you are in the right ground. Typical habit: radial. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify seidozerite?+
Where is seidozerite found?+
What rocks look like seidozerite?+
What minerals are found with seidozerite?+
What kind of rock does seidozerite form in?+
What is seidozerite used for?+
Find seidozerite on the map
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