diamond mines gemstones

  • Diamond: The mineral Diamond information and pictures

    Diamond has many unequaled qualities and is very unique among minerals. It is the hardest known substance, it is the greatest conductor of heat, it has the highest melting point of any substance (7362° F or 4090° C), and it has the highest refractive index of any natural mineral. Diamond is number 10 on the Mohs scale, and is approximately 4 times harder than Corundum, which is number 9 on ...

  • Texas Gemstones, Types and Location in Texas

    Genuine Texas gemstones may cost more than the equivalent type of stones from other parts of the world but they cost nothing like as much as diamonds. On the other hand, they are often rarer than diamonds, extra special to both the giver and the receiver and endowed with that essential Texan attribute – a really good story.

  • Top Ten Diamond Companies in the World - Petra Gems

    However, their diamond production remains among the highest on the planet, and they own a number of the world's richest mines, primarily in southern Africa. 8. Gem Diamonds Based in England, Gem Diamonds nonetheless operates worldwide, as any diamond company must be to achieve enough holdings to make it onto this list.

  • US Diamond Mines - Diamond Mining in the United States

    Two Commercial Diamond Mines. Two locations in the United States have been worked as commercial diamond mines. The first was a mine near Murfreesboro, Arkansas.It was worked as a commercial diamond mine by a succession of operators in the early 1900s but closed because the deposit was subeconomic. Today it is known as the "Crater of Diamonds" and is operated by the State of .