BH250-206c
Title
BH250-206c
Subject
Ijolite
Description
Major Minerals: plagioclase, nepheline, aegirine, aegirine-augite, spinel
Minor Mineral: sphene (titanite), magnetite
Optical Features and Texture:
Abundant nepheline makes this sample ideal for observing uniaxial negative optic axis and off-centered interference figures. Euhedral spinel crystals are well developed. Aegirine and aegirine-augite pyroxenes exhibit distinct pleochroism, contributing to the rock’s striking optical character.
Minor Mineral: sphene (titanite), magnetite
Optical Features and Texture:
Abundant nepheline makes this sample ideal for observing uniaxial negative optic axis and off-centered interference figures. Euhedral spinel crystals are well developed. Aegirine and aegirine-augite pyroxenes exhibit distinct pleochroism, contributing to the rock’s striking optical character.
Creator
Bereket Haileab
Source
From the rock collection of Bereket Haileab. Sample BH250-206c. Housed at Carleton College in Minnesota.
Type
Thin section and hand sample
Relation
Collection
Citation
Bereket Haileab, “BH250-206c,” BH250 Mineralogy Teaching Collection, accessed April 26, 2026, https://bereket-haileab.geology.sites.carleton.edu/items/show/261.