Scorodite Mineral Overview

• Mineral name: Scorodite
• Mineral class: Arsenate
• Chemical formula: FeAsO₄·2H₂O
• Crystal system: Orthorhombic
• Mohs hardness: 3.5–4
• Color range: Pale blue, green, bluish-green, gray
• Luster: Vitreous to dull
• Streak: White
• Cleavage: Poor
• Fracture: Uneven to earthy
• Specific gravity: Approximately 3.1–3.3
• Transparency: Transparent to translucent
• Common locations: Germany, Namibia, United States, Chile, Australia
• Uses: Collector mineral, indicator of arsenic-rich environments
• Similar minerals: Variscite, strengite, wavellite

Naming and Classification

Scorodite is an iron arsenate mineral, named from the Greek skorodon, meaning “garlic,” referring to the characteristic odor produced when arsenic compounds are heated.

It belongs to the arsenate mineral group, which includes minerals formed by the oxidation of arsenic-bearing المواد.

Physical and Optical Characteristics

Scorodite typically forms:

• Prismatic or dipyramidal crystals
• Crusts or earthy masses
• Radiating aggregates

Crystals can be small but well-formed and sometimes transparent.

Its color is most often pale blue to green, sometimes shifting toward gray depending on impurities and weathering. The color is one of its most distinguishing features.

The luster is vitreous on fresh crystal faces but may appear dull or earthy in massive forms. With a Mohs hardness of 3.5 to 4, scorodite is relatively soft.

Cleavage is poorly developed, and fracture is uneven.

Chemical Composition and Structure

Scorodite is composed of:

• Iron (Fe³⁺)
• Arsenate groups (AsO₄)
• Water (H₂O)

It is a hydrated mineral, meaning water is part of its structure. This contributes to:

• Its relatively low hardness
• Its formation in low-temperature environments

Formation and Geological Occurrence

Scorodite forms as a secondary mineral in the oxidized zones of arsenic-rich ore deposits.

Typical formation conditions include:

• Weathering of arsenic-bearing minerals such as arsenopyrite
• Interaction with oxygen and water near the surface
• Low-temperature environments

It is commonly associated with:

• Arsenopyrite
• Limonite
• Quartz
• Other secondary arsenates

These associations reflect oxidizing conditions in ore deposits.

Common Locations

Scorodite is found in many arsenic-rich mining regions:

• Germany: Classic locality
• Namibia: Well-known for attractive crystals
• United States: Various ore deposits
• Chile and Australia: Additional occurrences

Namibian specimens are particularly valued for their color and crystal form.

Uses and Practical Significance

Scorodite has limited practical use but is important in:

• Collector mineral: Valued for its color and crystal habit
• Environmental studies: Plays a role in arsenic mobility and stabilization in mine waste

It can help immobilize arsenic in certain conditions, making it relevant in environmental mineralogy.

Safety Considerations

Scorodite contains arsenic, which is toxic. When handling:

• Avoid inhaling dust
• Wash hands after contact
• Do not grind or heat the material

Careful handling is recommended for collectors.

Similar and Related Minerals

Scorodite can resemble other green to blue minerals:

• Variscite: Typically more stable green and softer
• Strengite: Similar structure but contains iron phosphate instead of arsenate
• Wavellite: Usually forms radiating clusters with different composition

Distinguishing scorodite often requires:

• Chemical testing
• Consideration of association with arsenic minerals
• Examination of crystal habit

Identification Notes for Collectors

• Look for pale blue to green crystals in oxidized ore zones
• Note moderate softness (3.5–4)
• Observe vitreous luster on fresh crystals
• Check association with arsenic-bearing minerals
• Handle with care due to arsenic content

Scorodite is a secondary iron arsenate mineral, recognized for its blue-green coloration and formation in oxidized arsenic-rich environments, and is primarily of interest to collectors and environmental studies.