| Diamonds, the hardest naturally occurring material | | | | “rooms”. High-tech machinery and |
| on earth, are forged only at the extreme | | | | computer technology have made hard-rock mining |
| pressures that exist deep in the Earth’s core | | | | less dangerous than it used to be, but the |
| and at the site of a meteor crash, in that single | | | | technique is still the most dangerous of the mining |
| moment of impact. Because they’re so rare, | | | | methods used today. |
| naturally formed diamonds are the most sought | | | | Placer Mining |
| after gem in the world. Here are some of the | | | | Known also as alluvial mining, placer mining is the |
| most common techniques people use to mine | | | | mining of secondary diamond deposits. Stones |
| diamonds. | | | | that end up in alluvial deposits tend to come from |
| Open Pit Mining | | | | kimberlite rock formations. Rivers and streams |
| Also called “strip mining” or “open-cast | | | | erode these kimberlite formations and transport |
| mining”, this technique requires the digging of | | | | the diamonds downstream. Miners then excavate |
| large, open pits in the ground, so that miners are | | | | them using hydraulic pressure systems so you |
| able to reach the diamond deposits hidden | | | | can purchase a San Diego diamond. Artisanal |
| underground. Open pit mining is used in sites | | | | techniques are also used, in small scale, to dig for |
| where the ground is too unstable to safely use | | | | gems in alluvial deposits. These techniques involve |
| tunneling techniques. Open pit mining is the most | | | | traditional methods, like sifting through river mud |
| common and lucrative form of diamond mining | | | | with sieves or pans. |
| and it has been a frequent target of | | | | Marine Diamond Mining |
| environmentalist protests, as its large land | | | | Marine diamond mining is the newest method of |
| displacement has the potential to harm the | | | | diamond mining. Because of the high-tech |
| ecosystems surrounding it. | | | | equipment required, marine diamond mining did not |
| Hard-Rock Mining | | | | become commercially practical until the 90’s. |
| As the name implies, hard-rock mining involves | | | | The technique involves drilling vertical and |
| drilling vertical tunnels or shafts, often miles deep, | | | | horizontal tunnels in the ocean floor. Underwater |
| into sites composed of hard rock. Horizontal | | | | vehicles crawl along the seabed and dig for |
| tunnels are also dug so as to connect the various | | | | minerals and gems. |
| vertical shafts and various underground | | | | |