Synthetic rubies, sapphires and other types of gems are easy to find in the marketplace. Many stores sell them, and they account for a very significant percentage of the rubies and sapphires sold today. There is nothing wrong with selling them and nothing wrong with buying them. However, the essential part of the transaction is…

Rubies and sapphires have been highly sought after in many parts of the world for over one thousand years. Deposits that produce high-quality stones of good color have attracted enormous amounts of attention and have been heavily exploited. As a result, buyers who need large quantities of quality stones are having a harder time finding…

Two of the more spectacular events in the history of gemstone mining occurred when heat treatment discoveries enabled geuda (a milky white to brownish corundum, found mainly in Sri Lanka) to be converted into beautiful blue gems. Worthless corundum had suddenly become valuable! Until then the worldwide resource of blue sapphire rough was becoming more…

Most gem-grade corundum forms in metamorphic rocks, such as schist or gneiss; or in igneous rocks such as basalt or syenite. However, gem corundums are rarely mined from the rocks in which they form. Mining small gems from hard rock is possible, but it is very expensive, and many of the gems are broken during the mining process. Fortunately, corundum is very hard…

Ruby and sapphire are extremely popular gemstones. Virtually every jewelry store that features colored gemstones in jewelry will have a generous portion of their display dedicated to ruby and sapphire items. Ruby is the most popular red gemstone, and sapphire is the most popular blue gemstone. The pie chart on this page shows the share…

Just like ruby, sapphires are subjected to a wide variety of heat and fracture-filling treatments. And, just like ruby, any heat, fracture-filling or other type of treatment should be disclosed to buyers. Spectacular Heat Treatment Results: Some rough materials that have no trace of blue color can be heated to produce a spectacular blue. Some…

Trace amounts of iron and titanium can produce a blue color in corundum. Blue corundums are known as “sapphires.” The name “sapphire” is used for corundums that range from a very light blue to a very dark blue color. The blue can range from a greenish blue to violetish blue. Gems with a rich blue to violetish…

Very few specimens of corundum have a natural color within the range required for a ruby. Very few also have the clarity required to produce a nice faceted stone. Long ago, people who prepared gem materials for cutting began experimenting with ways to improve their color and clarity. Physical Properties of Corundum: Chemical Classification Oxide Color A…

Rubies are gem corundums with a dominant red color. The color can range from orangy red to purplish red or brownish red. The most desirable color range is a pure vibrant red to a slightly purplish red. The red color of ruby is produced by the presence of chromium in the gem. A small trace of chromium…

Ruby and sapphire both serve as modern birthstones. Ruby is the birthstone for the month of July. Sapphire is the birthstone for the month of September. They are excellet choices for birthstones because they are well know gems and because many people love red and blue gemstones. Ruby and sapphre are not inexpensive gems and that…