Natural Amethyst Brazil, Marquise

Natural gems refer to gemstones that are formed in nature through natural geological processes, without human intervention. These gems are prized for their beauty, rarity, and durability. Some well-known examples of natural gems include:

1. Diamond: Formed deep within the Earth under high pressure and temperature conditions, diamonds are prized for their brilliance and hardness.

2. Emerald: A variety of the mineral beryl, emeralds are known for their vivid green color. They often contain inclusions which are considered part of their character.

3. Ruby: A red variety of the mineral corundum, rubies are highly valued for their rich color and rarity.

4. Sapphire: Another variety of corundum, sapphires come in various colors, with blue being the most famous. They are prized for their hardness and brilliance.

5. Opal: Known for its iridescent play-of-color, opals are formed from silica-rich solutions that fill voids or fissures in rock formations.

6. Topaz: Topaz occurs in a range of colors, but the most valued are the golden yellow to orange hues. It forms in igneous rocks and cavities within granitic pegmatites.

7. Amethyst: A purple variety of quartz, amethyst gets its color from irradiation, iron impurities, and the presence of trace elements. It is relatively abundant compared to some other gems.

8. Aquamarine: A blue variety of beryl, aquamarine is known for its light blue to blue-green color, reminiscent of the sea.

These are just a few examples, as there are many other types of natural gems, each with its own unique characteristics and formation processes.