Rubies are gemstones that are known for their red color and hexagonal shape. Large rubies are often more expensive than diamonds because naturally occurring rubies are harder to find and considered to be more rare than diamonds. Rubies are usually heat treated to bring out their natural color and reduce the amount of milky particulate in the stone. Synthetic and natural rubies have a wide range of uses in modern life.
Rubies are used extensively in jewelry. The gemstone is often set in a precious metal like platinum or gold and can be used as the primary stone in a given piece or to augment other stones like diamonds. Rubies are very tough, making them easy to maintain and relatively resistant to nicks or cracks caused by daily wear and tear.
In some devices, moving parts depend on bearings for their flexibility. Bearings are small balls that cause certain parts of a machine to move or rotate. If friction is a concern for the device, bearings can be crafted out of rubies. Rubies are smoother than most metals and result in less friction when used as bearings, but the overall cost of the device is likely to rise exponentially if rubies are a component. The most common application for jewel bearings is in the moving parts of mechanical watches.
Like diamonds, rubies excel at transmitting light from one location to another with a minimal loss of energy. Because of this inherent trait, rubies are often used as primary components in precision lasers. Ruby lasers usually have a red tone and are often used in range finding equipment for the military and surveyors. Ruby is also notable for producing a laser that is visible to the human eye, unlike many other solid-state lasers.
Rubies have a long history of myths and lore. Some rubies have been said to change colors in the presence of danger, while others have been famed for bringing wealth and fame to their owners. Some people believe that the presence of a ruby will ensure good luck and good fortune for the person who wears it, though these beliefs have largely died out in Western culture. Gemstones of this nature were usually attached to some sort of jewelry or lucky charm.
References and ResourcesGem Society: Ruby
In Depth Info: The Ruby
Bird Precision: Jewel Bearings Solve Light Load Problems
Minerals.net: THE PRECIOUS GEMSTONE RUBY