Opal is a relatively soft gemstone, with a hardness rating of 5.5 to 6.5 on the Mohs scale. This makes it softer than many other popular gemstones, such as diamonds, which are rated at 10 on the Mohs scale. Because of its relatively low hardness, opals should be handled with care and protected from hard knocks or abrasions.
There are several popular cuts for opals, including the cabochon cut, which is a smooth, rounded cut that is often used for opals with a strong play-of-color. Another popular cut for opals is the oval cut, which is a elongated version of the round cut and is often used for opals with a more subtle play-of-color. The heart shape is also a popular cut for opals, as it allows for the gemstone's play-of-color to be displayed to its full advantage.
The biggest opal ever discovered was the Olympic Australis, which was found in 1956 in Coober Pedy, South Australia. The opal weighed in at 17,000 carats (3.4 kg) and was cut into several smaller stones, including a pear-shaped stone that weighed more than 4,000 carats.
Opals are mined in a number of countries around the world, including Australia, which is the largest producer of opals in the world. Other countries where opals are mined include Brazil, Mexico, the United States, and Peru.
In terms of jewelry, opals can look great when cut into a heart shape and set in white gold, such as in a Claddagh ring. The white gold helps to accentuate the gemstone's play-of-color and adds a touch of elegance to the piece. Whether you are looking for a unique and beautiful piece of jewelry or want to symbolize your love and commitment, an opal Claddagh ring set in white gold is an excellent choice.