Large Vivianite Crystal Cluster in Matrix – São Gabriel da Cachoeira, Brazil – 1.98 lbs

This large cabinet-sized vivianite specimen from the São Gabriel da Cachoeira area of Brazil features multiple substantial crystals embedded throughout a richly textured, iron-bearing matrix. Weighing nearly two pounds and reaching approximately 7 inches, it has an imposing geological presence and offers dramatically different views from every angle.

Several elongated vivianite crystals emerge from deep cavities across the primary display face. Their broad bladed forms exhibit pronounced longitudinal striations, glassy reflective surfaces, and partially exposed terminations. While the crystals appear nearly black or midnight blue under ordinary lighting, focused illumination reveals saturated forest green, emerald, teal, and electric blue within their thinner edges and translucent sections.

The largest blades form a striking central concentration, while additional crystals appear in upper, side, and lower pockets. This distributed crystallization creates far greater visual complexity than a specimen centered around a single isolated crystal. Natural contacts, recessed growth areas, and partial crystals preserve the formation’s rugged character.

Its surrounding matrix ranges from mustard yellow and ochre to rust brown, creating exceptional contrast with the dark blue-green vivianite. The reverse is primarily natural iron-rich matrix with granular textures, rounded cavities, and smaller mineralized pockets.

Measuring approximately 5 × 3 × 7 inches, this substantial specimen combines multiple large vivianite crystals, intense hidden coloration, bold matrix contrast, and impressive cabinet-scale presentation.

Specifications

Primary Mineral: Vivianite

Formation: Multiple large bladed vivianite crystals embedded within iron-rich matrix cavities

Locality: São Gabriel da Cachoeira area, Amazonas, Brazil

Weight: 1.98 lbs, approximately 898 grams

Dimensions: Approximately 5 × 3 × 7 inches

Color: Midnight blue, near-black, forest green, emerald, teal, electric blue, ochre, mustard yellow, and rust brown

Crystal Habit: Elongated bladed-to-prismatic crystals with broad reflective faces and longitudinal striations

Display Face: Several major vivianite crystals distributed among recessed matrix pockets

Reverse: Predominantly natural ochre-brown matrix with cavities and granular iron-rich textures

Luster: Vitreous across exposed vivianite faces; earthy to subtly reflective across the matrix

Transparency: Translucent along thinner crystal sections and edges, appearing opaque in thicker areas

Chemical Formula: Fe₃(PO₄)₂·8H₂O

Mineral Class: Hydrated iron phosphate

Crystal System: Monoclinic

Mohs Hardness: Approximately 1.5–2

Display Size: Large cabinet specimen

Condition: Natural mineral specimen with inherent crystal contacts, incomplete terminations, cleavage features, edge irregularities, internal fractures, inclusions, cavities, surface deposits, and extraction-related contacts

Exact specimen shown

About Brazilian Vivianite

Vivianite is a hydrated iron-phosphate mineral celebrated for its intense blue-green coloration and strongly reflective bladed crystals. Fresh or thinner material may appear green, while natural oxidation can progressively deepen the color toward blue-green, navy, and nearly black.

Bright directional lighting reveals the remarkable color concealed within this specimen’s darkest crystals. This lighting response is especially noticeable along thin edges, internal fractures, and more translucent crystal sections.

Vivianite is soft, cleavage-prone, and sensitive to prolonged light exposure. Display it away from direct sunlight and strong ultraviolet light. Handle the piece by its solid matrix, avoid water and chemical cleaners, and remove dust only with a soft dry brush or gentle air blower.

Collector Notes

This specimen features:

• Natural vivianite from the São Gabriel da Cachoeira area of Brazil
• Large 1.98-pound cabinet size
• Impressive approximately 7-inch profile
• Multiple substantial bladed vivianite crystals
• Broad glassy and highly reflective crystal faces
• Strong longitudinal growth striations
• Deep blue-green to nearly black surface coloration
• Emerald, teal, and electric-blue transmitted-light highlights
• Crystals distributed across several matrix cavities
• Ochre, mustard-yellow, and rust-brown iron-rich matrix
• Dramatic mineral and color contrast
• Highly dimensional natural formation
• Distinctive front, side, and reverse views
• Exact specimen pictured

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You will receive the exact specimen shown.
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