Birthstones are precious or semi-precious gemstones that are associated with each month. Each month has a different stone, for instance, April’s birthstone is diamond. Birthstones dates back to the breastplate of Aaron which contained twelve gemstones representing the twelve tribes of Israel. The current list dates back to 1912 with only one addition since then – the tanzanite was added to December. According to many legends, birthstones (particularly when worn during it’s assigned month), have healing and therapeutic powers.
There are four precious stones: rubies, emeralds, sapphires, and diamonds. Occasionally, pearl, opal, or jade are listed as precious gemstone, but they are typically regarded semi-precious. These four precious stones have traditionally been the most expensive and sought-after gems.
Some of the more common semi-precious stones are alexandrite, agate, amethyst, aquamarine, garnet, lapis lazuli, moonstone, opal, pearl, peridot, rose quartz, spinel, tanzanite, tourmaline, turquoise, and zircon, and the list goes on. Every other gemstone that isn’t one of those four precious stones is considered to be semi-precious.
This separation between precious and semi precious has no real scientific backing. For example, emeralds are a variety of beryl, as are aquamarines. An emerald is a precious stone, while an aquamarine is semi-precious. When this categorization came about, it was mainly due to the value and rarity of the 4 precious gemstones compared to the rest. Today, some semi precious gemstones can be worth much more than a precious stone. As an example, many natural pearls garner huge prices, often worth more than a low quality precious diamond, ruby, emerald, or sapphire. Spinels are another example. Additionally, many semi-precious stones can be more rare than some of the precious. Demantoid garnets or tsavorite garnets, and many other semi-precious gemstones that are hard to find, harder to mine, and produced in much lower quantities than precious gemstones.
Cubic zirconia is a man-made product with no natural counterpart. The name “Cubic” refers to the crystal symmetry and “Zirconia” is the chemical composition (zirconium oxide). Cubic zirconia is not to be confused with the gemstone zircon. The only thing they have in common is that they both contain the element zirconium.