Santafeite is a complex rare arsenate mineral that occurs as small, dark, platy crystals or thin crusts in oxidized manganese deposits. It is primarily identified by its association with vanadium-rich mineralization and is mainly sought after by advanced mineral collectors for its complexity.
Is this santafeite?
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 santafeite with a known reference. Santafeite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Santafeite leaves a brownish-black streak.
- 3Read the lusterHold the specimen under a strong light. Santafeite typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: black, brownish-black.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, crusts, or massive aggregates.
Often confused with
Santafeite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Hausmannite is the harder of the two (Mohs 5-5.5 vs. 3); streak differs — Santafeite leaves brownish-black, Hausmannite leaves brownish-red.
How to tell apart: Romanèchite is the harder of the two (Mohs 5-6 vs. 3); streak differs — Santafeite leaves brownish-black, Romanèchite leaves shiny brownish black; luster reads submetallic on Santafeite and submetallic to dull on Romanèchite.
Often found alongside santafeite
Minerals reported to co-occur with santafeite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaMn²⁺₄Ca₂(Mn³⁺,V⁵⁺)O₂(AsO₄)₄·8H₂O
- Mohs hardness
- 3
- Density
- 3.5 g/cm³
- Colors
- Streak
- Brownish-black
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals, Crusts, Or Massive Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Hydrothermal Manganese-vanadium Deposits
- Typical price
- $50-300 per specimen depending on size and rarity
Where rockhounds find santafeite
Classic worldwide localities
- Aztec Mine, Eldorado district, Clark County, Nevada, USA
Field-hunting tip
Look in oxidized hydrothermal manganese-vanadium deposits country — that is the host setting where santafeite typically forms. If you start seeing calcite, hausmannite, birnessite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, or massive aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find santafeite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
