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Everything You Need to Organize Your Specimens

Volcanic glass with snowflakes embedded throughout.

Black, soft; most widely mined.

Gray to brown mudstone with abundant silt.

Hematite-cemented quartz; orthoquartzite.

Typical green-gray, fissile, clay-rich.

White, very dark green, and very dark red to light red granoblastic intergrowth of wollastonite, diopside, and andradite.

Gray, fine, friable, with abundant small sanidine crystal fragments.

Light gray, with flow structure.

Chlorite-mica with perfect slaty cleavage.