Diamond (gemstone) Diamond (gemstone) A diamond (from the "adámas", meaning "unbreakable", "proper", or "unalterable") is one of the best-known and most sought-after gemstones. Diamonds have been used as decorative items since ancient times; some of the earliest references can be traced to 25,000 - 30,000 B.C. The hardness of diamond and its high dispersion of light—giving the diamond its characteristic "fire"—make it useful for industrial applications and desirable as jewelry. Diamonds are such a highly traded commodity that multiple organizations have been created for grading and certifying them based on the "four Cs", which are color, cut, clarity, and carat. Other characteristics,
Kimberlite tailings at higher temperature to obtain Zeolite-A. The product is useful as builder in detergent formulation. With a view to assessing the potential use of kimberlite tailings in road works, the Central Road Research Institute engaged in a detailed laboratory study. Kimberlite tailings were characterized to determine their physical engineering properties. Results indicate that kimberlite tailings are a marginal material and possess adequate strength for use in the construction of rural roads. The feasibility of utilizing this material for the construction of various layers of road pavement by adopting stabilization techniques was investigated. A study was also undertaken to assess the