Photos of rocks with mineral grains in random orientation. Click on any photo for a larger image. Some of the larger images may be on other web sites and will open in a new window.

Red Sandstone with random

random-hs_001. Vesicular, randomly-oreinted plagioclase phenocrysta in a vesicular olivine basalt from the Pololu volcanic series, Kohala Volcano, Hawaii, USA. Centimeter grid for scale.

Andesite lava sample photo

random-hs_002. The white plagioclase phenocrysts and the darker hornblende and biotite crystals are randomly oriented in this 1.7 Ma andesite sample from Sutter Buttes, CA, USA. Smithsonian display (NMNH 116619). The field of view is approximately 25 cm across.

Diabase outcrop photo

random-hs_003. Pinkish plagioclase phenocrysts are randomly oriented in this diabase porphyry from Winter Island, Salem, MA, USA. The field of view is approximately 15 cm across.

Mafic Igneous Rock photo

random-hs_004. Randomly oriented crystals of plagioclase, hornblende, nepheline, and magnetite in a nepheline monzodiorite (essexite) from Mt. Johnson, Quebec, Canada. Wards Collection of North American Rocks sample W-32.