Uricite

Chemical formula: C<sub>5</sub>H<sub>4</sub>N<sub>4</sub>O<sub>3</sub>

Uricite is a rare organic mineral, a crystalline form of uric acid, found in guano deposits.

## Characteristics Uricite is an organic mineral, representing the naturally crystallized form of uric acid. It forms very small, prismatic or acicular crystals, rarely exceeding 1 mm in length. It usually occurs as aggregates, coatings, or as a component of bat and seabird guano. Crystals can be colorless, white, or yellowish, often with a silky luster. ## Physical Properties This mineral is very soft and light. Its Mohs hardness is approximately 1.5, and its density is close to 1.89 g/cm³. Crystals exhibit a silky or vitreous luster and are transparent to translucent. ## History and Name The mineral's name comes from its chemical composition – uric acid. It was described as a mineral in 1973 by George E. Mustoe, who identified it in bat guano samples from Toppin Creek Cave in Washington State, USA.

Properties

Mohs hardness
1.5
Luster
Silky
Streak
White
Density
1.89
Cleavage
Good on {100}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Uricite is difficult to identify visually without specialized equipment. Its key features include its occurrence in guano, very low hardness (it can be scratched with a fingernail), and characteristic, fine, prismatic crystals. It dissolves in hot water and alkaline solutions. ## Distinguishing from similar minerals It can be confused with other organic minerals found in guano, such as brushite or weddellite. Differentiation usually requires chemical analysis (e.g., infrared spectroscopy) or crystallographic analysis (X-ray diffraction). ## Crystal forms It forms elongated, prismatic or acicular crystals, often grouped into radiating aggregates or rosettes. Crystals are usually very small, sub-millimeter in size.

Geological environment

## Genesis Uricite is a mineral of organic origin. It forms as a result of the crystallization of uric acid, a metabolic product of birds and bats. It forms under dry conditions within guano deposits, in caves or on islands. ## Mineral associations It co-occurs with other organic minerals and phosphates typical of guano environments, such as brushite, weddellite, whitlockite, and hydroxyapatite. ## Localities Confirmed occurrences of this mineral are few. Besides the type locality in Toppin Creek Cave (Washington, USA), it has been identified in bat guano in caves in South Australia (Naracoorte) and in seabird guano on islands off the coast of Peru.

Rarity

Very rare

For collectors

## Quality criteria Due to its extreme rarity and small crystal size, any well-defined and analytically confirmed Uricite specimen is scientifically valuable. For collectors specializing in organic or systematic minerals, the presence of visible, even microscopic, crystals on a guano matrix is most important. Specimens with well-formed, larger crystals (over 1 mm) would be exceptionally valuable.

Care and storage

## Cleaning Uricite specimens are extremely delicate and sensitive to water. Mechanical cleaning is not recommended. If absolutely necessary, a stream of compressed air can be used to remove loose dust particles. ## What to avoid Contact with water, which can dissolve or damage the crystals, must be strictly avoided. The mineral is sensitive to moisture, elevated temperatures, and all chemicals. It should be protected from direct sunlight. ## Storage Uricite specimens should be stored in sealed, dry containers, preferably with a desiccant (e.g., silica gel). Due to its fragility and softness, vibrations and contact with harder minerals should be avoided.

External references

Sources

Read more