Diamonds

The hardest and most brilliant of all precious gems. Drills are equipped with diamond tips in order to cut through hard rock. It is also a transparent gem that has been cut and polished and is highly valued.

Diamond usage can be divided into two categories; gem diamonds and industrial diamonds. Many industrial diamonds are synthetically produced, but at high costs. Uses include lapidary for grinding or polishing gems, optics and glass, drill bits, surgical equipment, saws for cutting resistant materials, shaping very fine wires or to dress turning, boring and milling tools.

Information about the processing of diamonds once they are mined, including illustrations of the process.

Geologic processes create two basic types of diamond deposits, referred to as primary and secondary sources. Primary sources are the kimberlite and lamproite pipes that raise diamonds from Earth's mantle, where they originate. Secondary sources, created by erosion, include such deposits as surface scatterings around a pipe, concentrations in river channels, and fluxes from rivers moved by wave action along ocean coasts, past and present. Mining of these deposits depends upon sufficient concentration and quality of diamonds.

Geologic processes create two basic types of diamond deposits, referred to as primary and secondary sources. Primary sources are the kimberlite and lamproite pipes that raise diamonds from Earth's mantle, where they originate. Secondary sources, created by erosion, include such deposits as surface scatterings around a pipe, concentrations in river channels, and fluxes from rivers moved by wave action along ocean coasts, past and present. Mining of these deposits depends upon sufficient concentration and quality of diamonds.

Mining of a diamond-bearing pipe starts with the excavation of a pit into the pipe. In this process, called "open-pit" or "open-cast" mining, the initially loose and eventually hard ore material is removed with large hydraulic shovels and ore trucks. Hard rock is drilled and blasted with explosives so the broken material can be removed. When deep, rich ore warrants it, the mining goes underground with vertical shafts descending to horizontal drifts, or passageways that enter the pipe. The crushed ore is then conveyed to skips that carry the ore up the vertical shaft for processing.

An overview of diamond clarity as well as information about how to grade a diamond with photographs and classifications.

An explaination of diamond color and value with examples of how to classify the color of a diamond from D (good color) to Z (poor color).

To date, Africa has produced over 75%, in value, of the world's diamonds with more than 1.9 billion carats worth an estimated $US 158 billion mined. Mining activities are centered around South Central Africa, with diamonds being produced primarily from kimberlite mines (South Africa, Angola, DRC, Ghana, Tanzania, Lesotho and Botswana), followed by alluvial dredging operations (Angola, CAR, Namibia and South Africa) and offshore marine diamond activities (South Africa and Namibia).

Today diamonds are mined in about 25 countries, on every continent but Europe and Antarctica. For 1,000 years, starting in roughly the 4th century BCE, India was the only source of diamonds. In 1725, important sources were discovered in Brazil, and in the 1870s major finds in South Africa marked a dramatic increase in the diamond supply. Additional major producers now include several African countries, Siberian Russia, and Australia.
It is a modern misconception that the world's diamonds come primarily from South Africa: diamonds are a world-wide resource. The common characteristic of primary diamond deposits is the ancient terrain that hosts the kimberlite and lamproite pipes that bring diamonds to Earth's surface.

A report on the future of stock for Namco, which seeks for high quality diamonds off the Namibian coastline with mentions of the entire diamond sector and De Beers' stockpiles.

Article highlighting the growing partnership between De Beers, the world's largest diamond miner and other South African diamond industries and the growing Indian diamond industry.