Page 9 - Curriculum Visions Dynamic Book

 This fossil ammonite has been cut in half so that you can see how its original form has been replaced by calcite. The calcite appears as the grey in-filling to the shell segments. In a few cases you can see how the calcite has formed in small cavities, giving delicate crystals.
lava: the material that flows from a volcano.
mineral: a solid substance made of just one element or chemical compound. Calcite is a mineral because it consists only of calcium carbonate; halite is a mineral because it contains only sodium chloride; quartz is a mineral because it consists of only silicon dioxide.
prospector: a person who is exploring for geologically rich deposits of metals and gemstones.
 This rhombohedral- shaped crystal is typical of calcite. The faces are parallelograms.
 Crystals of calcite
growing in a small cavity
in a limestone rock. Notice
the limestone fossils. There are more examples of fossils cast in limestone on the next page.
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