Rubies symbolize power and protection

• Ruby is one of the four precious gemstones.  The others are emerald, sapphire, and diamond.  Ruby comes from the Latin "rubens" meaning red.
• Rubies are made of corundum.  Corundum comes in many other colors, but those colors are classified as sapphires.  Pink corundum is sometimes referred to as pink sapphire and other times is referred to as pink ruby depending on the hue, region, and personal opinion.  
• Ruby gets its red coloring from trace amounts of chromium.  Ruby measures 9 on the Mohs Scale of Hardness, second only to diamond and matched with sapphire. This makes ruby an extremely hard and durable gemstone. 
• https://www.thespruce.com/ruby-facts-2042968