BH250-59
Title
BH250-59
Subject
Kyanite-staurolite-garnet schist
Description
Major Minerals: garnet, staurolite, biotite, quartz, orthoclase, plagioclase, kyanite
BH250-59 – Kyanite–Staurolite–Garnet Schist
This schist contains major minerals: garnet, staurolite, biotite, quartz, orthoclase, plagioclase, and kyanite. Garnets occur in two textural generations—pre-tectonic crystals showing inclusion trails that cut across schistosity, and syn-tectonic crystals aligned with the foliation. Kyanite appears as long, prismatic, and distinctly bladed crystals, indicative of high-pressure metamorphic conditions. Staurolite is well developed and typically intergrown with biotite.
Quartz exhibits undulatory extinction. The rock’s protolith is pelitic, suggesting derivation from Al-rich mudstones or shales subjected to medium- to high-grade regional metamorphism.
BH250-59 – Kyanite–Staurolite–Garnet Schist
This schist contains major minerals: garnet, staurolite, biotite, quartz, orthoclase, plagioclase, and kyanite. Garnets occur in two textural generations—pre-tectonic crystals showing inclusion trails that cut across schistosity, and syn-tectonic crystals aligned with the foliation. Kyanite appears as long, prismatic, and distinctly bladed crystals, indicative of high-pressure metamorphic conditions. Staurolite is well developed and typically intergrown with biotite.
Quartz exhibits undulatory extinction. The rock’s protolith is pelitic, suggesting derivation from Al-rich mudstones or shales subjected to medium- to high-grade regional metamorphism.
Creator
Bereket Haileab
Source
From the rock collection of Bereket Haileab. Sample 59. Housed at Carleton College in Minnesota.
Type
Thin section
Relation
Collection
Citation
Bereket Haileab, “BH250-59,” BH250 Mineralogy Teaching Collection, accessed April 25, 2026, https://bereket-haileab.geology.sites.carleton.edu/items/show/68.