Meliphanite Mineral Overview
- Mineral name: Meliphanite
- Mineral class: Silicate (tectosilicate)
- Chemical formula: (Ca,Na)₂Be(Si,Al)₂O₆(F,OH)
- Crystal system: Tetragonal
- Mohs hardness: 5–6
- Color range: Yellow, honey-yellow, brownish-yellow, colorless
- Luster: Vitreous
- Streak: White
- Cleavage: Perfect (one direction)
- Fracture: Uneven
- Specific gravity: Approximately 2.9–3.0
- Transparency: Transparent to translucent
- Common locations: Norway, Sweden, Russia, Canada
- Uses: Collector mineral, rare gemstone
- Similar minerals: Beryl, danburite, feldspar
Naming and Classification
Meliphanite is a beryllium-bearing silicate mineral, named from the Greek meli, meaning “honey,” referring to its characteristic yellow color.
It belongs to a small group of beryllium silicates, making it geochemically important due to the presence of:
- Beryllium (Be)
Physical and Optical Characteristics
Meliphanite typically occurs as:
- Prismatic or tabular crystals
- Granular or massive aggregates
Its most distinctive feature is its honey-yellow to golden coloration, which may also appear:
- Pale yellow
- Brownish-yellow
- Occasionally nearly colorless
The luster is vitreous, giving it a bright, glassy look.
With a Mohs hardness of 5–6, it is moderately hard but not highly durable.
Cleavage (Key Feature)
Meliphanite exhibits:
- Perfect cleavage in one direction
This can cause crystals to break along smooth planes, which is important for identification and handling.
Chemical Composition and Structure
Meliphanite is composed of:
- Calcium (Ca)
- Sodium (Na)
- Beryllium (Be)
- Silicon (Si)
- Aluminum (Al)
- Fluorine (F) and hydroxyl (OH)
It has a framework (tectosilicate) structure, somewhat similar to feldspars but modified by:
- Beryllium incorporation
- Fluorine and hydroxyl content
Formation and Geological Occurrence
Meliphanite forms in alkaline igneous environments, particularly in:
Nepheline Syenites
- Silica-poor, sodium-rich rocks
Pegmatitic and Late-Stage Crystallization Zones
- Highly evolved magmas
Typical formation conditions include:
- Presence of beryllium and fluorine
- Alkaline, silica-undersaturated environments
It is commonly associated with:
- Nepheline
- Sodalite
- Aegirine
- Other rare-element silicates
Common Locations
Meliphanite is relatively rare and found in:
- Norway: Classic locality
- Sweden: Similar alkaline complexes
- Russia: Kola Peninsula
- Canada: Rare occurrences
Scandinavian deposits are especially well-known.
Uses and Practical Significance
Meliphanite has limited practical use:
Collector Mineral
- Attractive honey-colored crystals
- Rare and geologically interesting
Gemstone Use
- Occasionally faceted
- Rare due to cleavage and scarcity
It has no significant industrial application.
Similar and Related Minerals
Meliphanite can resemble:
- Beryl: Harder and typically hexagonal
- Danburite: More durable and lacks perfect cleavage
- Feldspar: Similar appearance but different composition
Cleavage and beryllium content help distinguish meliphanite.
Identification Notes for Collectors
- Look for honey-yellow to pale yellow crystals
- Note perfect cleavage in one direction
- Check moderate hardness (5–6)
- Observe vitreous luster
- Consider association with alkaline igneous rocks
Meliphanite is a rare beryllium-bearing silicate, recognized for its distinct honey-yellow color and occurrence in alkaline igneous environments, making it a specialized and appealing mineral for collectors.
