Delvauxite

A variety of Minerals

What is Delvauxite?

Delvauxite, also known as borickite, is a yellow to brown to dark brown amorphous mineral, sometimes forming a botryoidal mass. Its chemical formula is CaFe4(PO4,SO4)2(OH)8•(4-6)H2O. and it may sometimes form stalactites. It was first described in 1838 by Belgian chemist, Dumont and dedicate to J.S.P.J. Delvaux de Fenffe (1782–1863). It was found in Bernau, Liege, Belgium and Stredocesky, Czech republic.

Market Value Factors

Pricing varies for every rock and mineral, so use these universal factors to gauge Delvauxite before comparing listings or appraisals.

Size & Weight

Larger, intact specimens usually command higher prices.

Rarity & Demand

Scarce material or popular varieties sell at a premium.

Condition & Finish

Chips, repairs, and heavy wear lower value; clean prep helps.

Treatment & Provenance

Untreated specimens with documented locality are prized.

Applies to all rocks & minerals.

Delvauxite Localities Map

See where Delvauxite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

Map preview

North ZoneCentral RidgeSouth Basin

Quick Facts

Physical Properties

Color: Yellowish brown, brownish black, reddish, chestnut-brown
Hardness (Mohs): 2.5
Density: 1.85 g/cm³
Streak: Yellow, pale brown

Chemical Properties

Chemical Formula: CaFe₄(PO₄,SO₄)₂(OH)₈ · 4-6H₂O not confirmed
Elements: Ca, Fe, H, O, P, S

Also Known As

DelvauxiteFouchéiteFouchéritePicite

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Delvauxite FAQs

How do I identify Delvauxite?

Delvauxite can be identified by its hardness of 2.5 on the Mohs scale, Yellowish brown color. Look for these key characteristics when examining specimens.

What color is Delvauxite?

Delvauxite typically appears in Yellowish brown, brownish black, reddish, chestnut-brown. Color can vary depending on impurities and formation conditions.

How hard is Delvauxite?

Delvauxite has a hardness of 2.5 on the Mohs scale. This makes it a soft mineral that can be scratched easily.