A gemstone is a piece of mineral that is used to make jewelry or other forms of adornment. There are many types of gemstones which are valued for certain properties such as their color and luster. For instance, diamonds are not only precious stones, but are used as cutting tools because of their hardness. Gemstones are divided into precious and semi-precious stones.
Red corundum is known as ruby, and sapphire is any other color of corundum. After diamonds, sapphire is the second hardest substance known to man. Sapphire comes in many colors, even though blue is the color most people are familiar with. There are pink, yellow, purple, brown, white and green sapphires. There is a very rare variety of sapphire that displays different colors in different light. For instance, this type of sapphire is blue in natural light and violet in artificial light.
Amethyst is a part of the quartz family that is found in alluvial deposits around the world. Amethyst is the purple variant of quartz and is the most valuable member of that family. Amethyst acquires its purple color when manganese is present in clear quartz. Amethysts come in several shades such as deep purple, lavender, light lilac and mauve. The best-quality amethysts have a deep purple color. The depth of purple in any amethyst sample is determined by the quantity of manganese it contains.
Amber is actually sticky resin that oozed from prehistoric pine trees between the Pleistocene and Carboniferous geological periods. As the resin oozed from the trees, material like insects, feathers and other small objects became entrapped in it. The resin fossilized to become amber. The rarity and perfection of whatever object is trapped in the amber is what determines its value. The color of this gemstone ranges from a dark brown to a clear lemon yellow.
Jade is a term used to refer to all forms of nephrite and jadeite, which are two similar minerals. However, jadeite is more expensive because its green color is more intense than nephrite. The most expensive variety of jade is known as imperial jade, and it is mined in Myanmar. Jade is also mined in Central and South America and Mexico. Jade also comes in rarer hues of pink, black, purple and yellow. Another variety, which has a leek green color, is mined in Lake Baikal, Russia.