Provenite

Cap Blanc-Nez

AreaRestricted accessDraft data

50.9250° N, 1.7094° E · ± 1 km

Marcasite from Pas-de-Calais, France, with photos of specimens from this locality.

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Minerals found here

Marcasite

Marcasite at Cap Blanc-Nez

Classic sedimentary marcasite trees and nodules enclosed in Cretaceous chalk

A loose, complete cluster of marcasite crystals from the chalk cliffs at Cap Blanc-Nez, about 3 cm across.
A loose, complete cluster of marcasite crystals from the chalk cliffs at Cap Blanc-Nez, about 3 cm across.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
A rosette of lustrous marcasite crystals on chalk matrix from Cap Blanc-Nez.
A rosette of lustrous marcasite crystals on chalk matrix from Cap Blanc-Nez.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
An undamaged rosette of pagoda-like brassy marcasite crystals from Cap Blanc-Nez, about 3.4 cm wide.
An undamaged rosette of pagoda-like brassy marcasite crystals from Cap Blanc-Nez, about 3.4 cm wide.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Formula
FeS₂
Morphology
Multi-twinned crystal trees; nodules; radiating aggregates
Typical size
Crystal groups may reach several centimetres
Color / luster
Tin-white to pale bronze metallic; may tarnish iridescent
Associated minerals
Chalkpyrite
Surface features
Branching and radiating growth in chalk
Twins
Multiple repeated twins; pseudo-fivefold forms
Availability
No longer available
History
Classic Channel-coast locality; collecting is now prohibited

Sources: SRC-017

About Marcasite →

Geology of the locality

Setting
Sedimentary marcasite in Cretaceous chalk
Type
Sedimentary
Host rock
Chalk
Region
Pas-de-Calais
Country
France

Known for multi-twinned crystal trees, nodules and radiating aggregates; collecting is prohibited in the protected site. Position of the Cap Blanc-Nez headland.

Sources: SRC-017 SRC-024

Sources

  1. SRC-017 · Website
    Marcasite encyclopediaLe Comptoir Geologique · Le Comptoir Geologique
  2. SRC-024 · Website
    Cap Blanc-Nez - WikipediaWikipedia contributors · 2026 · Wikipedia

Draft data from the Provenite workbook. Check entries against the cited sources before relying on them. Photos are open-licence images from Wikimedia Commons; the author and licence are given with each photo.