Chalcedonies include many types of ... Many minerals form beautiful crystals, but the most prized of all are gemstones. Uncut gems often look fairly ordinary–like rocks. It's only when they ...

What FACTS ABOUT ROCKS do you know? They are abundant on earth, and yet little is known about them. These facts will increase your knowledge of the rocks.

A compound is a substance that contains two or more elements close elementA pure substance that is made from only one type of ... sandstone are all examples of sedimentary rocks.

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to ...

Some minerals in rocks and organic matter (e.g., wood, bones, and shells) can contain radioactive isotopes. The abundances of parent and daughter isotopes in a sample can be measured and used to ...

All plants require 17 elements ... review the mineralogical composition of common rocks that make up the soil parent material (Table 1). Primary minerals form at elevated temperatures from cooling ...

the genesis of accessory minerals such as REE phosphates in all rock types, the origins of economic concentrations of minerals and petroleum, the make-up of the atmosphere, ocean and life on Earth ...