Magnolite
Chemical formula: Hg¹⁺₂Te⁴⁺O₃
Magnolite is an extremely rare mercury tellurite, forming microscopic, acicular crystals of white or yellowish color.
Properties
- Mohs hardness
- 1-2
- Color
- Colorless, creamy white; also pale yellow green (Mountain Lion Mine).
- Luster
- Silky, Adamantine
- Streak
- Colorless, also light brown (Mountain Lion Mine)
- Density
- 0
- Cleavage
- Perfect on {001} Good perpendicular to {001}
- Fracture
- Uneven
- Transparency
- Transparent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification Identification of magnolite is primarily based on its characteristic mode of occurrence – as delicate, acicular or capillary crystals forming woolly aggregates. Its co-occurrence with other tellurides and tellurites in the oxidation zones of deposits is also crucial. Identification usually requires chemical analysis (EDS) to confirm the presence of mercury and tellurium. ## Distinguishing from Similar Minerals Magnolite can be confused with other secondary, acicular minerals, such as chalcotrichite (an acicular variety of cuprite) or some zeolites. Differentiation is based on the geological context (associations with tellurium minerals) and analytical studies. Unlike many similar sulfate minerals, magnolite is not water-soluble. ## Crystal Forms Magnolite forms elongated, acicular or capillary (fibrous) crystals, often grouped into radiating aggregates, bundles, or chaotic, felted masses resembling felt or glass wool.
Geological environment
## Genesis Magnolite is a secondary mineral, formed by the oxidation of primary tellurides (mainly gold and silver tellurides) in the presence of mercury. It forms under near-surface conditions, in the weathering zones of hydrothermal ore deposits. ## Mineral Associations This mineral co-occurs with other oxidation products of tellurides. Its most common associated minerals are: native mercury, native tellurium, calomel, emmonsite, mackayite, as well as native gold, quartz, and fluorite. ## Localities The most important and classic magnolite localities are in the USA, in Colorado (Magnolia, Cripple Creek, and Gold Hill districts). Its occurrence has also been confirmed in the El Plomo mine in Honduras and the Wendy mine in La Paz County, Arizona (USA).
Rarity
Very rare
For collectors
## Quality Criteria The collectibility of magnolite primarily depends on the richness and abundance of its aggregates on the rock matrix. Most valued are specimens with dense, woolly aggregates of microscopic, but clearly visible needles, covering a significant area of the host rock. A contrasting matrix, such as dark quartz, enhances visual appeal. Due to its microscopic nature, the purity and size of individual crystals are not key criteria. ## Popular Localities By far the most sought-after specimens by collectors come from historical localities in Colorado, USA, especially from the Magnolia District, which is the type locality. Specimens from these localities have historical significance and serve as a reference point for this mineral.
Care and storage
## Cleaning Magnolite specimens are generally not cleaned due to their extreme delicacy. Any attempts at mechanical cleaning, even with a soft brush, can irreversibly destroy the microscopic crystals. Dust can be removed very carefully using a photographic air blower, from a safe distance. ## What to Avoid Avoid any contact with water, chemicals, and ultrasound. The crystals are extremely brittle and sensitive to shocks and temperature changes. As a mercury-containing mineral, it should be handled with caution – avoid inhaling dust and wash hands after any contact. ## Storage Magnolite requires storage in stable conditions, in a closed, airtight "micromount" box that protects it from dust, moisture, and mechanical damage. It should be kept away from sources of vibration and direct sunlight.