Oxo-magnesio-hastingsite is a rare member of the calcic amphibole group, typically identified through sophisticated mineralogical analysis. It occurs primarily as prismatic crystals within alkaline igneous complexes. Collectors look for these dark, lustrous crystals in environments associated with iron-rich metamorphic or metasomatic processes.

Hardness
5-6
Mohs
Luster
Vitreous
Streak
Pale Gray
Transparency
Translucent

Is this oxo-magnesio-hastingsite?

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 oxo-magnesio-hastingsite with a known reference. Oxo-magnesio-hastingsite sits at Mohs 5-6 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Oxo-magnesio-hastingsite leaves a pale gray streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Oxo-magnesio-hastingsite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: black, dark green, brown.
  • 5
    Look at form & habit
    Crystal system: monoclinic. Typical habit: prismatic crystals.

Often confused with

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

Often found alongside oxo-magnesio-hastingsite

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

All properties

Chemical formula
NaCa₂(Fe₃⁺₅)Si₆Al₂O₂₂(O)₂
Mohs hardness
5-6
Density
3.35-3.45 g/cm³
Streak
Pale Gray
Luster
Vitreous
Transparency
Translucent
Crystal system
Monoclinic
Crystal habit
Prismatic Crystals
Cleavage
Perfect On {110}
Rarity
Rare
Uses
Collector
Host rock
Alkaline Igneous Rocks
Typical price
$20-100 per specimen

Where rockhounds find oxo-magnesio-hastingsite

Classic worldwide localities

  • Finland
  • Russia
  • Sweden

Field-hunting tip

Look in alkaline igneous rocks country — that is the host setting where oxo-magnesio-hastingsite typically forms. If you start seeing plagioclase, quartz, biotite 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 oxo-magnesio-hastingsite?+
Mohs hardness is 5-6. It typically shows a vitreous luster. The streak is pale gray. Common colors include black, dark green, brown.
Where is oxo-magnesio-hastingsite found?+
Notable localities include Finland; Russia; Sweden.
How much is oxo-magnesio-hastingsite worth?+
Typical asking prices fall in the range of $20-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like oxo-magnesio-hastingsite?+
Oxo-magnesio-hastingsite is most often confused with Hastingsite, Hornblende, Magnesio-hastingsite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with oxo-magnesio-hastingsite?+
Oxo-magnesio-hastingsite commonly co-occurs with Plagioclase, Quartz, Biotite, Magnetite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does oxo-magnesio-hastingsite form in?+
Oxo-magnesio-hastingsite typically forms in alkaline igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.
What is oxo-magnesio-hastingsite used for?+
Oxo-magnesio-hastingsite is used in collector.

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