Diamonds have been the world's premier status symbol since they were first excavated and used in works of art in India thousands of years ago. The use as a standard for wedding rings is more recent, however. They are believed to have first been used in this way in ancient Rome, but became a popular trend among European aristocracy in the 15th century.
In the United States, the diamond wedding ring became the standard in the 1940s. This was due to a major advertising push by the De Beers company, which had recently opened new mines in Africa that greatly increased the supply of these rare stones.
The formation of a diamond is a process that takes over one billion years, under intense heat and pressure in the mantle of the earth. The final step in the process is for it to be delivered to the earth's surface in rock as part of a volcanic eruption. Of course there are also now synthetic processes that can create one in as little as a day, but the most valuable and beautiful diamonds are naturally formed.
The final step in getting a diamond to market is the cut. There are quite a few different varieties, but the "round brilliant" is the one you see used in the majority of wedding rings and jewelry. Other popular varieties are the square or rectangular "princess cut," the oval-shaped "marquise cut" and the trimmed corners of the "radiant cut."
Diamond beads are a smaller and more affordable variant that are perfect for any artistic or jewelry project and sometimes give people feelings of fearlessness and clarity.
Tourmaline comes in a wide variety of vibrant colors, often with multiple colors in one stone. These stones were first discovered in Sri Lanka and imported to Europe in the 17th century, and were sometimes successfully passed off as rubies. It is mined all over the world, but most of the decorative gems now come from Brazil or various countries in Africa.
Tourmaline has a wide variety of uses. It is beautiful enough to simply be used for jewelry purposes, but it is also popular for spiritual practices and as an element of interior decoration. It is also the birthstone for the month of October.
Like diamond, topaz is both extremely hard and extremely lovely. Topaz usually forms in a shade of brown to yellow, but natural impurities can cause it to come out in a number of other brilliant colors.
Some states have adopted topaz as their official gemstone: the orange variety in Utah, and blue topaz in Texas. Orange topaz is also the birthstone of November.
"Rainbow" or "mystic" topaz is created by an artificial process that was developed in the 1990s, applying a special coating to give regular topaz a beautiful array of colors.
Sapphire is known primarily for a lovely deep blue hue, but these rare stones can actually occur in a few other colors and sometimes even with multiple colors. Colors other than blue are called "fancy," while those with more than one color are "parti." There is even an extremely rare variety that is clear.
Most of the interest in sapphire is in the primary blue variety, however, which is used in all sorts of jewelry and decoration purely for its rich and pleasing color. It is also September's birthstone and is sometimes given as a gift to celebrate a 45th wedding anniversary.
Sapphire is also widely used in alternative medicine to treat internal imbalances that cause restlessness.
Citrine is a type of quartz that appears on the color spectrum somewhere between yellow and brown, with a lot of variety in the particular hue between different stones. It is extremely rare to find citrine in nature, and most of what is on the market is created by treating another type of quartz (such as amethyst) with heat.
It has been used as a decoration since ancient Greece, and has also been connected to prosperity in several different cultures. Some spiritual practitioners see it as a cleansing and renewing stone that can be used to refresh both body and mind.
The rarer variety of opal that is classified as "precious" is prized because of its iridescent coloring. For much of human history, precious opal was found only in Slovakia and was extremely rare and valuable. The discovery of vast deposits across Australia made it more readily available and also made it that country's official gemstone.
Some alternative medicine practitioners believe that it can purify the blood, treat fevers and balance the water content of the body.
Hematite is a crystal found in iron that is usually black or red in hue, but on occasion is golden. It is commonly used in mourning jewelry, and some feel that the stone helps to ground them and provide them with motivation and self-confidence.