Sangeetha Pulapaka


In India in a VIP/politican's house/ a jewellery store! and before that they form in the Earth's crust.

Before venturing into a summary of the ways in which gems are formed, it would be good background to review where those processes are occurring. A crude geological model of our Earth can be made by using an apple. The Earth's crust or top layer (ranging from 3 - 25 miles deep, only 1% of the Earth's volume) is represented by the thin skin, its mantle accounting for over 80% of the volume is represented by the flesh (over 1800 miles thick), and the core is represented by, what else?, the core.

The core has a solid inner, and liquid outer, portion, and is the least known and studied part of the Earth. Most of the mantle consists of melted rock (magma) and giant segments of the Earth's crust along with the solid upper mantle, called "tectonic plates", float on this fluid rock and move slowly over it. The movement normally occurs at about the same rate your fingernails grow, but can be substantially faster when one plate suddenly slips in relation to another. The various ways in which these plates encounter each other, are responsible for many of the momentous events that shape our Earth, such as volcanism, earthquakes, and periods of mountain building.The diamond though, does not form in the earth's crust. It forms in the mantle.