Roweite is a rare borate mineral found almost exclusively in the unique metamorphic deposits of Franklin and Sterling Hill, New Jersey. It typically occurs as small, fragile acicular crystals or radial clusters associated with willemite and franklinite. Collectors value it for its limited occurrence and specific association with the world-famous Franklin mineral suite.
Is this roweite?
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 roweite with a known reference. Roweite 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: light brown.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: light brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular to prismatic crystals, often as radial or divergent aggregates.
Often confused with
Roweite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Roweite leaves light brown, Jarosewichite leaves reddish orange; luster reads vitreous on Roweite and subvitreous on fractured surfaces on Jarosewichite.
How to tell apart: Streak differs, so Roweite leaves light brown, Hodgkinsonite leaves white.
Often found alongside roweite
Minerals reported to co-occur with roweite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂Mn₂B₄O₇(OH)₆
- Mohs hardness
- 4.5
- Density
- 2.935 g/cm³
- Colors
- Streak
- Light brown
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular to prismatic crystals, often as radial or divergent aggregates
- Cleavage
- On {100}, fair; on {001}, {021}, poor
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Very rare in hydrothermal veins in a metamorphosed stratiform zinc orebody (Franklin, New Jersey, USA)
Where rockhounds find roweite
Classic worldwide localities
- Franklin, Sussex Co., New Jersey, USA
- Solongo boron deposit, Buryatia, Russia
Field-hunting tip
Where it forms: Very rare in hydrothermal veins in a metamorphosed stratiform zinc orebody (Franklin, New Jersey, USA). If you start seeing clinochrysotile, calcite, franklinite in float, you are in the right ground. Typical habit: acicular to prismatic crystals, often as radial or divergent aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify roweite?+
Where is roweite found?+
What rocks look like roweite?+
What minerals are found with roweite?+
What kind of rock does roweite form in?+
What is roweite used for?+
Find roweite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
