Silicates are compounds of silicon, oxygen and other elements. Silica (silicon dioxide), silicate, and aluminosilicate minerals make up over 90% of the Earth's crust. Naturally occurring silicates are important building materials and make up the clays...

Igneous rocks are classified by geologists using various schemes. One of the several schemes based on chemical composition divides igneous rocks into four categories according to silica (silicon dioxide, SiO2) content: (1) Rocks containing more than...

In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. This definition is broad enough to include species such as hexafluorosilicate ("fluorosilicate"),...

Scientists taking their first "sniffs of air" from planets outside our solar system are a bit baffled by what they didn't find: water.One of the more basic assumptions of astronomy is that the two distant, hot gaseous planets they examined must contain water in their...

The first "sniffs of air" of two huge far-away planets reveal that they seem to be missing water, a surprising finding amid weather unlike any planets in our solar system with blast furnace-like gusts amid supersonic winds.The absence of water from the atmosphere of both...