Brazilianite Mineral Overview

Mineral name: Brazilianite
Mineral class: Phosphate

Known Facts

• Chemical formula: NaAl₃(PO₄)₂(OH)₄
• Crystal system: Monoclinic
• Mohs hardness: 5.5–6
• Color range: Yellow, greenish-yellow, yellow-green
• Luster: Vitreous
• Streak: White
• Cleavage: Good in one direction
• Fracture: Uneven to subconchoidal
• Specific gravity: Approximately 2.9–3.0
• Common locations: Brazil, United States, Canada
• Uses: Gemstone, collector specimens
• Similar minerals: Amblygonite, montebrasite, apatite

Physical and Optical Characteristics

Brazilianite is best known for its:

• Bright yellow to yellow-green color
• Attractive, well-formed crystals

It typically occurs as:

• Prismatic or wedge-shaped crystals
• Clustered crystal groups
• Occasionally massive material

Crystals are often transparent to translucent, with gem-quality material showing good clarity.

The luster is vitreous, giving a glassy appearance. Due to its moderate hardness and good clarity, it can be cut as a gemstone.

Chemical Composition and Structure

Brazilianite has the formula:

• NaAl₃(PO₄)₂(OH)₄

It is a sodium aluminum phosphate, containing:

• Sodium (Na)
• Aluminum (Al)
• Phosphate groups (PO₄³⁻)
• Hydroxyl (OH)

It belongs to a group of secondary phosphate minerals, often formed by alteration of primary phosphates.

Its structure contributes to:

• Good crystal development
• Moderate hardness and cleavage

Formation and Geological Occurrence

Brazilianite forms primarily in granitic pegmatites, especially in phosphate-rich zones.

Typical formation conditions include:

• Alteration of primary phosphate minerals, such as:
  • Triphylite
• Late-stage crystallization in pegmatitic environments

It is commonly associated with:

• Apatite
• Quartz and feldspar
• Other secondary phosphates

These assemblages are characteristic of pegmatite phosphate mineral systems.

Common Locations

Notable occurrences of Brazilianite include:

• Brazil: Minas Gerais (type locality and major source)
• United States: New Hampshire and Maine
• Canada: Yukon

Brazil is the most important source, especially for gem-quality specimens.

Uses and Practical Significance

Brazilianite is valued primarily for:

Gemstone use

• Occasionally cut into faceted stones
• Appreciated for:
  • Bright yellow color
  • Good transparency

Collecting

• Highly sought after for:
  • Color and crystal form
  • Association with pegmatite minerals

It has no significant industrial uses.

Similar and Related Minerals

Brazilianite may be confused with:

• Amblygonite/Montebrasite: Often similar color but typically more massive
• Apatite: Can be yellow but usually harder and forms different crystals

Distinguishing features include:

• Bright yellow to greenish color
• Prismatic crystal habit
• Occurrence in pegmatite phosphate zones

Identification Notes for Collectors

• Look for yellow prismatic crystals in pegmatites
• Note association with phosphate minerals like apatite
• Check for moderate hardness (5.5–6)
• Observe vitreous luster and transparency
• Confirm locality, especially Minas Gerais specimens

Brazilianite is a sodium aluminum phosphate mineral, recognized for its bright yellow color and occurrence in pegmatite environments, and is valued both as a collector mineral and a minor gemstone.