Diamonds are recognized as April’s birthstone and are the world's most well known gemstone.  Diamond is the strongest and hardest known material and has the highest thermal conductivity of any material at room temperature. Diamonds are made up of carbon that was buried deep within the Earth under intense pressure and heat. They were made popular because loose diamonds are the hardest known substance. They do not easily break, crack or chip, though can be cut by a single blow. India began mining diamonds for diamond jewelry over a thousand years ago until they were found in other places. Today, most diamonds are mined in African countries, while mining is still done in partsof Australia, South America, Canada and Russia.

The traditional diamond is white, however diamonds can be found in a rainbow of colors because diamonds can be as colorful as any other gem. The occurrence of different hues is created by the presence of slight traces of other elements beside carbon. The type of element inclusion determines the color. Pink and blue diamonds are especially popular and have been sold at higher dollars per carat than any other loose gemstones in history. Red, green, and purple diamonds are among the rarest.

Diamonds are the center stone of choice for the engagement rings. The tradition began when Archduke Maximilian of Austria gave the first diamond engagement ring to Mary of Burgundy in 1477.

Diamonds are found in a variety of shapes; baguette, emerald, heart, marquise, oval, pear, princess, radiant, round and trillion. The most popular diamond shape has been the round brilliant because people believed it to be an "ideal cut" that displayed the most brilliance and sparkle in a diamond. However, other shapes can be as brilliant, such as the princess cut and trilliant cut.

Diamonds are mounted in several different types of settings, each displaying the diamonds in different ways.

• Bar: Metal bars hold the loose diamonds in a channel-like setting.
• Bezel: The metal is formed to fit around the diamond’s girdle.
• Channel: A row of small diamonds set in a groove.
• Chevron: V-shaped prongs that usually hold a marquise or princess-cut diamond for solitaire style rings.
• Invisible: Diamond set in a groove without visible prongs.
• Pave: Small stones are embedded to look like the piece is paved with loose diamonds.
• Prong: Several prongs hold the diamonds to let light pass through without interference.
• Prong settings can hold loose diamonds up high to display the beauty and radiance.