TERRIUM — A mineralogy cabinet


Ludlamita

Ludlamita is a mineral with formula Fe₂(PO₄)₂·4H₂O, in the Fosfatos group. This specimen comes from Cabeça de Cachorro, São Gabriel da Cachoeira, Amazonas, Brasil and joined the Terrium collection in 2025.

Ludlamita from Cabeça de Cachorro, São Gabriel da Cachoeira, Amazonas, Brasil — Terrium

Description

Emerald-green prismatic ludlamite crystals with highly lustrous faces, parallel growth and well-defined edges. Three-dimensional arrangement on a brown, nodular-textured matrix.

About Ludlamita

Uncommon on the market. Ludlamite forms in phosphate-rich hydrothermal environments. Its deep green colour, vitreous lustre and prismatic habit make it much valued. It can be confused with vivianite, but it is more stable. Much Brazilian ludlamite occurs on rather unattractive rocky and sandy matrices, though with well-formed crystals.

About the locality

The Cabeça do Cachorro region, in the heart of the Brazilian Amazon, hosts little-worked deposits. Ludlamite from this area became known at Sainte-Marie-aux-Mines in 2019 for its superior quality. However, many ludlamite and vivianite specimens from Brazil on the market have been extracted illegally from protected areas, such as indigenous lands or national parks. Discovered in 2017–18; by the following year it was already at Sainte-Marie-aux-Mines.

Technical data

Catalogue No.
0037
Composition
Fe₂(PO₄)₂·4H₂O
Name
Ludlamita
Group
Fosfatos
Category
Meritum Persé
Matrix
Matriz terrosa nodular
Mine
Cabeça de Cachorro
District / Municipality
São Gabriel da Cachoeira
Province
Amazonas
Country
Brasil
Size (cm)
4 x 4.5
Weight
43 g
Acquired
2025
Etymology
Named in honour of Thomas L. Ludlam, a 19th-century American collector.
Quality
Muy buena
Value trend
Estable

Related specimens

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