According to the GIA:
"Ruby is the most valuable variety of the corundum mineral species, which also includes sapphire. Rubies can command the highest per-carat price of any colored stone. This makes a ruby one of the most important gems in the colored stone market." Source (https://www.gia.edu/ruby-description)
"Chromium is the trace element that causes the ruby’s red, which ranges from an orangy red to a purplish red." (http://www.gia.edu/ruby)
The redness of the Ruby comes from how much chromium is present or absence. The more chromium the red is brighter and the less chromium the lighter the color. The color is what makes the ruby so unique. The color red seems to catch people’s attention even if it’s a lighter red. Having high iron content can cause the ruby to have a red fluorescence, which causes it to have an extra glow. Its shiny redness is appealing to the eyes. The color red seems to draw people it must have some kind of power or maybe people just think of love or lust when they see it.
Rubies were significant back in the medieval times. It was important for people to show off their wealth. During those times the ruby retained its importance with the birth of the western world and became one of the most sought-after gems of European royalty and upper class people. I guess you can say if you were rich in those times than you had jewels or gems to show how wealthy you were. It separates you from the poor people. Many medieval Europeans wore rubies as a good luck charm or a religion artifact, which guarantee health, wealth, wisdom, and success in love.
Still today people desire to have a ruby as a symbol of passion, as well as an ideal romantic gift. Even consumers are attractive to its lushes red color because what it represents. Everyone wants wealth and success. Most people believe in good luck charms whether it’s a ring, a rabbit’s foot, or just something that you believe has power.
Few people outside the gem industry realize the true nature of a gemstone’s journey from the mine to the counter of a store. Whether the gem is being offered to consumer’s at a traditional jewelry store’s counter, an internet shopping site, or a television broadcast the journey always involves a great deal of effort. Tons of earth and countless hours of labor are needed to being a gem from mine to market. Source: (http://www.gia.edu/ruby)
Red can also represent emotions, such as love, anger, passion, fury, objects of power and desires. Objects of power can be red fast cars. Most red cars are stopped the most by the law than any other color cars. Red roses symbolize love on Valentine’s Day or just when you want to be romantic. Early cultures believe rubies similarity to the redness of the blood that flowed through their veins, and believed that rubies held the power of life.