Diamond, rubies, emeralds and sapphires are the most precious of gems. The classification of precious as opposed to semi-precious has to do with the gem's beauty, rarity, hardness and transparency. The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material and has a rating from one to 10, with one being the softest and 10 being the hardest. It is the most commonly used rating scale for minerals.
The diamond is named for the Greek word "adámas," which means unbreakable. It is the hardest known natural substance on the planet. The diamond is also the most popular of gemstones because of its superlative beauty, transparency and rarity.
On the Mohs scale of mineral hardness, the diamond rates a 10, which is the highest possible rating.
In ancient times, the diamond was a talisman against danger and gave strength, good luck and manhood to its owner.
The ruby is named for the Latin word for red, "ruber." It is distinguished by its pink to red color caused mainly by trace amounts of chromium. Generally, the darker and richer the red, the more valuable the ruby. For the ruby to be of any real value, it must be transparent. Rubies that are opaque or semi-opaque are not considered gems and are of little value.
On the Mohs scale of mineral hardness, the ruby rates a nine.
The ruby is a red variety of the mineral corundum, or aluminum oxide, like the diamond and the sapphire. The ruby, in actuality, is a red sapphire since the ruby and sapphire are identical other than their colors.
In ancient times the ruby was considered the blood stone and was believed to prevent death from bleeding.
The name "emerald" is derived from the Latin word "esmaraldus." It's green color comes from trace amounts of chromium and vanadium. The deeper the green, the greater the value of the emerald.
The emerald is of the mineral beryl, unlike the diamond, ruby and sapphire, which are of the mineral corundum.
On the Mohs scale, the emerald is given the rating of 8, making it the softest of the precious gems.
In ancient times the emerald was thought to grant immortality, as well as won the admiration of rulers and armistice of enemies.
Sapphire is derived from the Greek word "sappheiros," meaning "blue stone." The most commonly known color of sapphire is blue, but the sapphire can be several different colors. The red sapphire is the ruby. The blue sapphire gets its color from chromium and titanium.
The sapphire is of the mineral corundum, like the diamond and the ruby.
On the Mohs scale, the sapphire is given the rating of nine.
In ancient times the sapphire was thought to ward off despair and fire and be a remedy for madness and boils.