Classified by texture and composition Normally contains no fossils Rarely reacts with acid Usually has no layering Usually made of two or more minerals May be light or dark colored Usually made of mineral crystals of different sizes Sometimes has openings or glass fibers May be fine-grained or glassy extrusive
Classified by texture and composition Often contains fossils May react with acid Often has layers, flat or curved Usually composed of pieces cemented or pressed together Has great color variety Particle size may be the same or vary Usually has pores between pieces May have cross-bedding, mud cracks, worm burrows, raindrop impressions
Classified by texture and composition Rarely has fossils May react with acid May have alternate bands of light and dark minerals May be composed of only one mineral, ex. marble & quartzite May have layers of visible crystals Usually made of mineral crystals of different sizes Rarely has pores or openings May have bent or curved foliation
Did you know that the Taj mahal is built entirely out of marble
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption such as the ones at Yellowstone National Park in the US and Glen Coe in Scotland. They are sometimes confused with volcanic craters.