Rocks and Minerals

Rocks and minerals
(What I learned from the dynamic earth site)
“Earth’s history is written on pages of stone. Since our planets birth 4.6 billion years ago, rocks have been continually forming, and over time, changing from one kind to another. Every rock preserves part of this ancient and ongoing story”
Notes from:
“Rocks made to order”
To start, there are about 10,000 aggregate operations in the U.S alone, putting one close to every major city. We use about 3-billion tons of crushed stone, sand, and gravel every year, nearly half of all the earth-like materials mined in the U.S. Today, the concrete foundations and facades of homes, schools, offices, and stores are all built with with materials that are dug up from underground. An average new house in U.S is constructed with about 400 tons of quarried materials.


Did you know…
Roads are made from crushed rock, sand and gravel and they have many different layers.



“Gems & Minerals”
Minerals occur naturally and are made by heat and pressure, minerals can also be made chemically. Minerals all have crystalline structures meaning that their structures are all geometrical structures. Some well known types of minerals are quartz and crystal. The 88 naturally occurring elements of crystals are made of atoms of different sizes and properties that combine in many different ways to form crystals. The huge range of temperature on earth contributes to the crystals diversity in shape. But the variety is not endless: certain shapes or variations occur again and again.
Any of the nearly 4000 minerals could be cut into a gemstone-if a crystal of sufficient size and quality were found. But only about 15 kinds of minerals are commonly used for gemstones. They combine desirable colors, shapes or optical effects with hardness and availability.



Did you know…
Minerals make up the Earth, the Moon, and meteorites that come crashing into Earth from other parts of the solar system.