| The diamond has always been the king of jewels | | | | sapphires are of Sri Lankan origin, while |
| and enjoyed tremendous popularity over the | | | | Madagascar is also a common source. The |
| ages. However, there are a few other gemstones | | | | 423-carat Logan Sapphire at the Smithsonian is |
| as well, that, like the diamond, can be classified as | | | | one of the most famous such stones in the world. |
| precious stones. These are the ruby, the sapphire, | | | | Emerald |
| and the emerald. The pearl is also often included in | | | | The emerald (from Semitic izmargad, meaning |
| this category, although strictly speaking, it is not a | | | | green) is a variety of the mineral beryl, with trace |
| precious stone. | | | | impurities like chromium and vanadium contributing |
| Ruby | | | | to its green color. In ancient times, emeralds were |
| The ruby is composed of the mineral corundum | | | | mined in Egypt and Austria. Now they mostly |
| (aluminium oxide), with its characteristic red color | | | | come from three main emerald mining areas in |
| due to the presence of chromium. Its name | | | | Colombia. In some cultures, the emerald is the |
| originates from ruber, Latin for red. Price i | | | | traditional gift for the 55th wedding anniversary. It |
| determined by color, with the brightest and most | | | | is also commonly used to commemorate the 20th |
| valuable "red", called pigeon blood-red, commanding | | | | and 35th wedding anniversaries. The Gachala |
| the highest numbers. After color, clarity dictates | | | | Emerald, a 858-carat stone donated to the |
| price with the clearer stones being more | | | | Smithsonian by New York jeweler Harry Winston, |
| expensive. The Mogok Valley in Upper Myanmar | | | | is one of the largest emeralds in the world. |
| (Burma) has for centuries been the source for | | | | Pearl |
| the best rubies, but reserves have depleted. One | | | | The pearl is a gem created within the soft tissue |
| of the world's largest and finest rubies, at 23.1 | | | | of a living shelled mollusk. It is made of calcium |
| carats, was donated by businessman and | | | | carbonate in minute crystalline form, deposited in |
| philanthropist Peter Buck to the Smithsonian. | | | | conentric layers. Natural pearls are created |
| Sapphire | | | | accidentally when a small enters a shelled mollusk |
| The sapphire (from Greek sappheiros, meaning | | | | and settles inside. The mollusk, irritated by the |
| blue), like the ruby, is also a variant of the mineral | | | | intruder, forms a pearl sac of external mantle |
| corondum. Although blue is the most well known | | | | tissue cells and secretes the calcium carbonate to |
| hue, sapphire is any color of corundum except | | | | cover the irritant. This secretion process is |
| red. Purple sapphires contain trace amounts of | | | | repeated many times, thus producing a pearl. |
| vanadium while those with titanium are colorless. | | | | Perfect natural pearls are extremely rare and |
| Iron impurities contribute to a green color. If both | | | | strings can sell for hundreds of thousands of |
| titanium and iron are present, the sapphire is | | | | dollars. |
| colored a brilliant blue. Many of the famous | | | | |