Lazaridisite

Chemical formula: (Cd²⁺S⁶⁺O₄)₃(H₂O)₆·₂H₂O

Lazaridisite is a very rare, hydrated cadmium sulfate, forming colorless, acicular crystals with a vitreous luster.

## Characteristics Lazaridisite is a mineral from the sulfate group, chemically a hydrated cadmium sulfate. It occurs as very small, acicular or hair-like crystals, which usually form tangled aggregates or crusts. Individual crystals are colorless and transparent, and their small size makes them appear white in aggregates. It is a secondary mineral, forming under specific conditions. ## Physical Properties Lazaridisite crystals exhibit a vitreous luster. Due to their microscopic size and delicate nature, determining hardness and density is difficult. The mineral is brittle. ## Colors and Varieties Lazaridisite is colorless. No colored or commercial varieties are distinguished. ## History and Name The mineral was named in honor of Lazaros Lazaridis (born 1957), a Greek mineral collector from Lavrion, who found the first samples. It was approved as a new mineral species by the International Mineralogical Association (IMA) in 2019 (IMA2019-030). The type locality is the Hilarion Mine in the Lavrion region, Greece. ## Uses Lazaridisite has no industrial application. It is of purely scientific and collecting interest as a very rare mineral.

Properties

Mohs hardness: 3
Color: Colorless
Luster: Vitreous
Streak: White
Density: 3.10
Fracture: Irregular/Uneven
Transparency: Transparent,Translucent
Crystal system: Monoclinic

Diagnostic features

## Identification Lazaridisite is difficult to identify visually without specialized equipment. Characteristic features include colorless, acicular crystals forming tangled aggregates on a rock matrix. It occurs in paragenesis with other secondary sulfates in the oxidation zones of ore deposits. Certain identification requires advanced analytical methods, such as Raman spectroscopy or X-ray diffraction (XRD). ## Differentiation from Similar Minerals It can be confused with other secondary sulfates of similar appearance, such as gypsum (especially its acicular variety, selenite) or epsomite. Gypsum is much more common and usually forms larger crystals. Differentiation from other rare cadmium sulfates, like voudourisite, requires chemical analysis. ## Crystal Forms The mineral forms very fine, elongated crystals with an acicular or hair-like habit. These crystals often occur as tangled, woolly, or felted aggregates and crusts on the surface of the host rock.

Geological environment

## Genesis Lazaridisite is a secondary mineral, formed as a result of oxidation processes (weathering) of sulfidic ore deposits, especially those rich in cadmium (e.g., containing greenockite or cadmian sphalerite). It forms under low-temperature conditions in oxidation zones, often in voids and fissures in rocks. Its formation is associated with the activity of sulfate-rich waters. ## Mineral Associations This mineral co-occurs with other secondary sulfates and minerals of the oxidation zone. In the type locality (Lavrion, Greece), it has been found in association with gypsum, voudourisite, niedermayrite, greenockite, and sphalerite. ## Localities The only confirmed occurrence of lazaridisite in the world is its type locality - the Hilarion Mine, in the Lavrion district, Attica region, Greece. This is a classic locality for many rare secondary minerals.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a lazaridisite specimen primarily depends on the richness and aesthetics of the crystal aggregates. Most valued are specimens with dense, well-formed clusters of acicular crystals, clearly visible on a contrasting rock matrix. Due to the microscopic size of the crystals, specimens are mainly evaluated under magnification. Association with other rare minerals from Lavrion is also important. ## Popular Localities The only known locality from which all available specimens originate is the Hilarion Mine in Lavrion, Greece. Specimens from this locality are highly sought after by collectors specializing in rare minerals and so-called "micromounts."

Care and storage

## Cleaning Lazaridisite specimens should not be cleaned wet. The mineral is water-soluble. For dust removal, a soft brush or carefully applied compressed air from a safe distance can be used. ## What to Avoid Contact with water, acids, and other chemicals that could dissolve or damage it must be strictly avoided. It should be protected from high temperatures, which can lead to dehydration and destruction of the crystal structure. Due to its brittleness, vibrations and impacts should be avoided. ## Storage Specimens should be stored in a dry place, preferably in a sealed, lidded box (micromount type), to protect them from atmospheric moisture and mechanical damage. Display should be in a closed cabinet away from heat sources.

External references

https://www.mindat.org/min-43257.html