The word "ruby" derives from the Latin word "ruber," which means red. Rubies have always been favored by those in roles of power as well as by those in love and are therefore considered a gemstone that involves a lot of emotion. Some cultures even have a fable regarding the source of the stone. It was told that rubies grew on trees, starting out as white buds and then blossoming into ripe red rubies ready to be picked. Rubies are mentioned in the Bible and have been used and appreciated in some of the most ancient cultures.

A ruby is an extremely strong stone, ranking 9.0 on the Mohs scale of mineral hardness. Natural rubies contain imperfections, including color impurities and inclusions of rutile needles referred to as "silk." These imperfections play an important role in detecting artificial rubies. Heat treatments are very common among most rubies today, conducted prior to the cutting of the stone. However, there are a few high-quality rubies that have not been treated, demanding high prices.

Gem-quality corundum displaying any shade of red or pink is considered a ruby. In the United States, specific standards regarding saturation must be met for ruby to fall into that category; otherwise, it is labeled a pink sapphire. The grading of a ruby's color considers three aspects: hue, saturation, and tone. Hue refers to the ruby's color as seen, while saturation determines the visibility and intensity of the color. Tone tells us the purity of the color, indicating whether it has secondary hues or is a pure tone.

Like diamonds, rubies are assessed based on the 4Cs: color, clarity, cut, and carat. Color is the most important factor in determining a ruby's value. The darker and more vividly colored rubies are the most sought after and expensive. Clarity also plays a role, with clear stones commanding higher prices. However, rubies without any needle-like rutile inclusions may indicate that the stone has undergone treatment.

For centuries, the majority of the world's rubies were mined in Mozambique and Myanmar (Burma), particularly the Mogok Valley. Additional sources for rubies include Thailand, Australia, Cambodia, Afghanistan, Brazil, Namibia, India, Japan, and Colombia. Myanmar is known for producing some of the finest rubies, and trade sanctions with the country have been lifted.

Natural rubies are minerals from the corundum family that have formed beneath the Earth's surface over millions of years. Lab-grown rubies, on the other hand, are created artificially. To identify the differences, it is important to know that most natural rubies have some sort of inclusion, while lab-grown rubies can be nearly flawless. Unusually low prices or flawless rubies are potential indicators of lab-grown stones. Examining the stone's structure through a microscope or requesting certification from an expert can provide certainty about a ruby's authenticity.

Rubies have been associated with power, wealth, and royalty throughout history. They were believed to possess protective abilities, safeguarding one's assets and personal health. Rubies are prestigious gemstones that can be affordable if smaller in size. They offer a warm and upbeat alternative to diamonds and are known for their emotional and spiritual benefits. They are associated with love, passion, courage, self-awareness, and finding one's true destiny.

Rubies have long been believed to possess specific abilities. They were associated with improving memory, liver problems, and neutralizing poison in various historical periods. Rubies symbolize love, passion, energy, and power. Some of the world's largest and most expensive rubies can be found in museums, such as the Sunrise Ruby and the Liberty Bell Ruby.

The most expensive ruby ever sold is the Sunrise Ruby, which fetched over $30 million in 2015. Other expensive rubies include the Burmese ruby and diamond ring and the Mogok Burmese ruby and diamond Cartier brooch. Factors such as size, color, quality, and origin contribute to a ruby's high price, with rubies from the Mogok deposit in Burma commanding significant sums.