Precious vs. Semi-Precious Gemstones
The difference between precious and semi-precious gemstones is rarity. Diamonds, rubies, sapphires and emeralds are very rare and are therefore considered to be precious stones; all other gemstones are considered semi-precious.
Natural vs. Lab-created Gemstones
Natural gemstones are found in nature, created in and mined from the earth. Natural gemstones are sometimes enhanced, which means they were treated in some way (such as heat) to improve their color and/or clarity.
Lab-created gemstones are made in a laboratories and are chemically, physically and optically identical to gems found in nature. Lab-created gemstones simply don't have the rarity or value of natural gemstones.
Color, Cut and Clarity
- Color - sometimes referred to as the gem's hue. Generally, gemstones with clear, medium-tone, intense and saturated primary colors are most preferred.
- Clarity - appearance of inclusions in the gem. Some gems, such as emeralds, are more likely to have inclusions, while gems like aquamarine and topaz generally have very few or no inclusions.
- Carat - weight of the gemstone. It is important to recognize that some gems are denser than others, so similarly sized stones of different varieties may differ greatly in cost. For example, a one carat ruby (very dense) is going to be smaller than a one carat emerald (less dense).