"PARKWAY PLASTICS, INC."

Lens holder for 50 mm lenses or mirrors for use with Eisco Optical Bench.

Gray to buff, with numerous ooliths and fossil fragments.

Fine to medium-grained with biotite.

Clear, pure cleavages, Mohs’ hardness of 2.

Gray, fine-grained, massive contact rock.

Bigger design for easy connections.

This set is economical, durable, and versatile.

Inexpensive yet accurate.

White, fibrous, silky luster.

Fine, common limestone; massive, and will fizzle with HCl.

Silvery, paragranite and muscovite-rich with medium garnet crystals.

Designed to provide a safe, convenient surface for laptops, tablets or books in a laboratory setting.

Shiny crystal clusters and crystalline groups, this 'fools gold' is brassy and leaves a black streak.

Fightly cemented, medium-to-coarse quartz grains.

Dark gray with abundant gas pocket vesicles.

Buff-colored, coarse, detrital limestone, with cemented shell fragments.