Lulzacite

Chemical formula: Sr₂Fe²⁺₃Al₄(PO₄)₄(OH)₁₀

Lulzacite is a rare strontium, iron, and aluminum phosphate, forming platy crystals of a characteristic grayish-green color.

## Characteristics Lulzacite is a complex phosphate belonging to the dussertite group. It occurs as small, platy or bladed crystals, rarely exceeding 1 mm in length. These crystals often form rosette-like or radial aggregates. The mineral is opaque and has a grayish-green color. ## Physical Properties Its Mohs hardness is 5.5 to 6. It has a vitreous luster and a density of 3.55 g/cm³. It exhibits no cleavage. ## Colors and Varieties This mineral is known exclusively in one color – grayish-green. No varieties have been distinguished. ## History and Name Lulzacite was discovered and described in 1999 by P. Pioleto, M. Pasono, P. Le Roch, and F. Pillard. Its name honors the French geologist Yvon Lulzac (1933-1995), who made significant contributions to the understanding of the geology of the Armorican Massif in France, where the mineral was first found. ## Uses Lulzacite has no industrial application. It is solely a mineral of scientific and collecting interest.

Properties

Mohs hardness: 5.5-6
Luster: Vitreous
Streak: White
Density: 3.55
Cleavage: None
Fracture: Uneven
Transparency: Opaque
Crystal system: Triclinic

Diagnostic features

## Identification Lulzacite can be identified by its characteristic grayish-green color, vitreous luster, and mode of occurrence – small, platy crystals forming rosette-like aggregates. The absence of cleavage is also a helpful feature. ## Distinguishing from Similar Minerals It may be confused with other green phosphates or silicates found in similar environments, such as some chlorites or epidote. However, definitive differentiation requires advanced analytical methods, such as spectroscopy or X-ray diffraction, due to the small size of the crystals. ## Crystal Forms It forms very small, thin, platy crystals with a hexagonal or rhombic outline. These crystals most often occur as radial or rosette-like aggregates, growing on the surface of the host rock.

Geological environment

## Genesis Lulzacite forms as a result of low-temperature hydrothermal processes acting on sedimentary rocks, particularly black shales. Its formation is associated with greenschist facies metamorphism. ## Mineral Associations This mineral co-occurs with quartz, siderite, goethite, apatite, monazite-(Ce), dussertite, crandallite, goyazite, and minerals from the chlorite group. ## Localities The only confirmed and typical locality for lulzacite in the world is the Bois-de-la-Roche quarry in Saint-Aubin-des-Châteaux (Loire-Atlantique, France). This is the sole site from which specimens of this mineral are obtained.

Rarity

Extremely rare

For collectors

## Quality Criteria The most valuable lulzacite specimens are those with well-formed, distinct crystals forming aesthetic, rosette-like aggregates. Contrast with a light host rock (usually quartz) also enhances the specimen's appeal. Due to the small size of the crystals, their sharpness and lack of damage, visible under magnification, are crucial. ## Popular Localities All collector specimens originate from the type locality – the Bois-de-la-Roche quarry in France. Material from this location is extremely rare on the market.

Care and storage

## Cleaning Lulzacite specimens should be cleaned mechanically only, using a soft brush to remove dust. Due to its rarity and small crystal size, contact with water and chemical agents, which could damage both the mineral itself and the host rock, should be avoided. ## What to Avoid Ultrasonic cleaners, all acids, and detergents should be avoided. The mineral should be protected from sudden temperature changes and prolonged exposure to direct sunlight. ## Storage Collector specimens of lulzacite, due to their small size and fragility, are best stored in enclosed "micromount" boxes, which protect them from dust, mechanical damage, and humidity.