| Henri Moissan (1852-1907) received the Nobel Prize in | | | | Diamonds and Tairus all utilize the HPHT method of |
| Chemistry in 1906. In 1892 theorized that by | | | | producing gem quality man made diamonds. Clear or |
| crystallizing carbon with pressure and heat from | | | | White diamonds must be produced in an environment |
| molten iron he could make diamonds. The then set | | | | that is free of impurities like nitrogen and boron which |
| out to prove his theory by designing and building an | | | | makes them very difficult and costly to produce. |
| electric-arc furnace. He subsequently was able to | | | | Most diamonds created by the HPHT method will |
| product several tiny stones that had the same | | | | contain some color. Yellow or orange tint occurs |
| properties as mined diamonds. Thus the start of the | | | | when nitrogen atoms replace 5 or more carbon |
| man made diamond race was born. | | | | atoms out of each 10,000 atoms. At a level of one |
| The experiment was successfully repeated by Ruffin | | | | or a few boron atoms for every million-carbon atom |
| in 1917 and again by Dr Willard Hershey in 1926. The | | | | is replaced, an attractive blue color results. |
| diamond that was created by Dr Willard Hershey is | | | | The second method used to produce gem quality |
| on display in Kansas at the McPherson Museum. | | | | diamonds is called Chemical Vapor Deposition (CVD). |
| Despite the earlier success, the following | | | | When pure carbon and hydrogen is heated to about |
| experimenters had great difficulty in reproducing the | | | | 1,8000 degrees Fahrenheit a plasma cloud is formed. |
| required temperatures and pressures needed by the | | | | As the plasma cools carbon will rain out of the |
| process and some of the experimenters even lost | | | | mixture and carbon atoms will be deposited on wafer |
| their lives to explosions. | | | | seeds. The wafers will grow at about 1/2 a millimeter |
| In 1941 General Electric was able to produce a one | | | | a day. The ability to control the injection of impurties |
| carat diamond but of very poor quality. It was not | | | | allows a greater measure of control in the final |
| until 1954 that General Electric was able to produce | | | | diamond composition than the HTHP method. Apollo |
| commercially synthesis diamonds of a size and quality | | | | Diamond uses the CVD method of producing the |
| to be used in the industrial abrasives market. Today | | | | larger and more expensive man made diamonds. |
| over 600 metric tons of commercially produced | | | | Man-made diamonds are very difficult to distinguish |
| diamonds are produced for the industrial abrasives | | | | from natural ones. A trained jeweler could tell the |
| market and about 26 metric tons of mined diamonds | | | | difference if he could detect the different growth |
| are produced for gemstone market yearly. | | | | patterns and the lack of inclusions. Inclusions are the |
| Today there are two methods used to produce gem | | | | tiny bits of material that are usually imbedded in a |
| quality diamonds. The first is the High Pressure High | | | | natural diamond and are considered a flaw. The ability |
| Temperature (HPHT). If pure carbon in put under | | | | to be able to control the amount and type of |
| pressures of 50,000 atmospheres and temperatures | | | | inclusion is vital to the ability of the man made |
| between 1100, and 1400 degrees Celsius will | | | | diamond to be used in semiconductor applications |
| reproduce the environment that creates diamonds | | | | which in turn will lead to the next generation of |
| inside the Earths core. | | | | computer chips. |
| Companies like Gemesis, New Age Diamonds, Adia | | | | |