Riebeckite var. Tiger Eye

Object/Artifact

-

Crater Rock Museum

Tigereye

Tigereye

Name/Title

Riebeckite var. Tiger Eye

Entry/Object ID

2015.1.4

Description

Chemical Composition: Na2(Fe,Mg)3Fe2Si8o22(OH) Crystal System: Monoclinic System Description: Common Name: Riebeckite var. Tiger Eye Chemistry: Na2(Fe, Mg)3Fe2Si8O22(OH)2 Group: Silicates Location: Pilbara, Australia Description: A thick slab with one cut and polished surface. 5/6 of it is a black and tan color and one edge is golden browns. It has the look of wood grain. Physical Charateristics: •Color is usually dark blue to black. •Luster is vitreous or silky in fibrous forms. •Transparency: Crystals are translucent. •Crystal System is monoclinic; 2/m. •Crystal Habits include slender prismatic to acicular, often aggregated crystals, columnar, granular and fibrous, asbestiform masses. A moss-like aggregate habit has been described when found in some igneous rocks. •Cleavage: is perfect in two directions at 56 and 124 degree angles. •Fracture is splintery to uneven. •Hardness is 5 - 6. •Specific Gravity is approximately 3.2 - 3.4 (average to slightly above average). •Streak is blue-gray. •Other Characteristics: Weakly pleochroic and crystals are striated lengthwise. •Associated Minerals are nepheline, quartz, almandine, aegirine, feldspars, micas and hematite. •Notable Occurrences include Socotra Island, South Yemen; Transvaal, South Africa; Schirmeck, Germany; Langesund, Norway; Krivoi Rog, Ukraine; Hamersley Range in Western Australia; Scotland; Madagascar; Quincy, Massachusetts; St Peter's Dome, El Paso County, Colorado; California; Oregon and Cumberland Hill, Rhode Island, USA. •Best Field Indicators are crystal habit, color, streak, cleavage and hardness. Fracture: Uneven Hardness: 6 Orthoclase Luster: Vitreous Rock Type: Sedimentary Specific Gravity: 3.2-3.4 Streak: Blue gray

Collection

RAGM Mineral Collection

Acquisition

Accession

2014.1

Source or Donor

Crater Rock Museum (unknown donors)

Acquisition Method

Gift

Dimensions

Width

5 in

Depth

1-1/2 in

Length

6-1/4 in

Location

Location

Display Case

DS-10

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Curtis Gardner

Date

May 10, 2023

Notes

Added current location while cleaning shelf