According to the guide, the most valuable amethysts are those that are categorized as medium reddish purple with a slight tint of brown.. This rare amethyst commanded between $64.00 and $70.00 as of March 2014. At the same time, the least valuable amethysts were those that were very light purple in color.
Geology and Sources of Energy. by Steve Sharp, P.E. Some of our mineral resources can be taken out of the ground and used for fuel. Raw materials have two sources: they can be grown or they can be mined. Coal, oil and gas are collectively called fossil fuels, because they formed from organic (living) matter. Uranium is also a source of energy that is taken out of the ground. These fuels that are mined are called non-renewable resources, because we can't replace them.
When most people think of fossils they think of dinosaur skeletons and large bones, but there are many different types of fossils to be found. Palaeontologists, people who study fossils, divide them into two major types-body fossils and trace fossils.Body fossils show us what a plant or animal looked like. The first type, body fossils, are the fossilised remains of an animal or plant, like bones, shells and leaves.he second type of fossil records the activity of an animal. Known as trace fossils, these include footprints, trackways, and coprolites (fossil poo!). Footprints and coprolites are trace fossils-they show us how an animal lived. There are lots of different types of fossil.