Ruby is the birthstone for July, and the 15th and 40th year anniversary gemstone.
Undoubtedly one of the rarest gemstones. This aluminum oxide gemstone can certainly protect itself, as it is the second hardest gemstone behind the diamond. The ruby’s extreme durability allow it to be cut into every size and shape, creating unique examples of fine jewelry.
Corundum is the host mineral in which ruby deposits are found; the trace elements introduced into the corundum determine whether or not a ruby is formed. When the coloring agent chromium is introduced, a ruby is produced, while other trace elements will produce the gemstones known as sapphires (iron, for example, is the element responsible for blue sapphire).
Historically the leading ruby-mining countries have been Myanmar (Burma) and Sri Lanka. Today, rubies are found in Thailand, Madagascar, Africa, and Vietnam. Due to the U.S. moratorium on gemstones and pearls from Myanmar, fine rubies are particularly difficult to obtain. Natural rubies are a very slow-growing crystal, making it rare to see a large ruby of almost any quality.
For more info, click on… https://www.gia.edu/ruby