| Peridot is a gemstone with a fascinating history. It | | | | Zabargad almost continuously for over 3,500 |
| is one of the oldest known gemstones, with | | | | years. But it is an interesting fact that the exact |
| ancient written records documenting the mining of | | | | location of the island was lost for several |
| peridot as early as 1500 B.C. It is a gem especially | | | | centuries and was only rediscovered in 1905. The |
| connected with ancient Egypt, and some historians | | | | tiny island, often shrouded in fog, is located about |
| believe that the famous emeralds of Cleopatra | | | | 35 miles off the Egyptian costal port of Berenica. |
| were actually peridots. | | | | Mining ended on Zabargad around the time of |
| In nature, peridot's history is different from that | | | | World War II. Today there are five major |
| of almost all other gems. Most gems are formed | | | | sources of peridot. Very fine specimens come |
| in the earth's crust. The two exceptions are | | | | from Burma, and new material from Pakistan has |
| peridot and diamond, which are formed much | | | | generated considerable excitement in the gem |
| deeper in the earth, in the earth's mantle. Peridot | | | | world. Arizona and New Mexico in the USA are |
| forms in magma in the upper mantle, about 20 to | | | | important producers of commercial grade peridot, |
| 55 miles deep; it is brought to the surface by | | | | and Vietnam and China especially are are |
| tectonic or volcanic activity. Diamond, by contrast, | | | | increasingly important suppliers. |
| is formed much deeper in the mantle, around 100 | | | | The largest known cut peridot is 310 carats and |
| to 150 miles below the surface, at extreme | | | | housed at the Smithsonian in Washington, D.C.; a |
| pressure and temperature. | | | | 192.75 carat stone is in the Diamond Treasury, |
| The main source of peridot in the ancient world | | | | Moscow; and a 146 carat peridot may be found in |
| was Topazos Island, now known as Zabargad or | | | | the Geological Museum in London, England. Peridot |
| St. John's Island, in the Egyptian Red Sea. The | | | | is a relatively inexpensive gemstone in small sizes, |
| island was discussed in the natural history of Pliny | | | | but the value goes up with stones over 5 carats, |
| the Elder (23-79 A.D.) as having been explored in | | | | with 10-15 carat stones very rare and expensive. |
| the fourth century B.C. Peridot was probably | | | | There is no known treatment to improve the |
| known originally as topaz; only much later did the | | | | color or clarity of peridot, so peridot is always an |
| name come to be applied to the gemstone we | | | | untreated gem. |
| know today as topaz. Peridot has been mined on | | | | |