Best (AAA) This category is made up of the top 10% of opal stones. Better (AA) 33% of available opal stones fall into this category. Good (A) This category includes the top 75% of available opal stones that are milky with no color play. The desirable color play is further broken down by the colors themselves.
Traditionally, red is considered the best prominent color, orange being the next most desirable, followed by green. However, preferred colors may vary depending on fashion or personal preference.
Opalsusually have a cabochon cut, which means they have a flat bottom with a soft, domed top. This cut is the best for showing the play of colors.
As for the shape, the oval and round ones are the most common, followed by the pear and marquise shape. We recommend these four shapes as the best way to show the beauty of opal. Since approximately one third of the stone has poor fire, the color grade of the opal would be greatly reduced. Although each opal is unique, it should be ranked based on standard factors rather than its emotional attractiveness.
On the other hand, consumers may see a higher or lower value in an opal than their professional grade may indicate. Assuming that creating an order to classify this gemstone (to determine the different degrees of saturation, the play of colors, the different patterns, as well as the brightness, transparency and hue) is not easy, an opal lover may find the analysis and evaluation of an opal quite difficult. Most high-end opals are free-cut to preserve weight, so this is a small factor, but it becomes more important in lower grade stones.