& gt Display more than 3 colors: The opal with the highest grade must display more than 3 colors.
& gt indispensable high saturation: saturation is also the purity of color. When every color change of an opal gem is bright, it is another excellent symbol.
& gt Judging the pros and cons from graphics: This is Opal's unique judging feature, and different color patterns also determine Opal's value. Because the color change of the opal surface appears as irregular corners or color points, the big corners with regular shapes are the best. Wonderful patterns are called multicolored, ribbons, straw, chaff, flags and so on. Some irregular patterns symbolize some beautiful things or look like a painting. Excellent patterns are very clear, including flowers, spins, lightning and flames. The poor pattern is vague, and only a few small color spots appear, such as moss and grass.
& gt05' s large size will always prevail: no matter what kind of gems you buy, carat weight is the key factor affecting the price. The thickness of the whole opal is related to the size and shape of the opal itself, which is an important factor to be considered and calculated when measuring the value.
& gt Multi-angle observation is safer: because the value of opal is completely determined by color, the more uniform the color, the higher the value. Therefore, when buying opal, we should pay attention to the overall effect of the color change of the gem and observe it from multiple angles. The brightness, saturation and color of high-quality opal run through, and there is no "blind zone".
& gt07 Choose flawless: Flaws are something that no gem wants to see, and all kinds of flaws will weaken the value of Opal. There are obvious cracks on the surface of opal, which will seriously affect the value. Opal with many fine cracks on its surface will also become worthless. Sometimes sand holes or other mineral impurities are found under or in colored opals. The color and pattern of high-quality opal should be continuous and change with different angles. When opal cannot produce a changing surface, the color presented from only one angle will also devalue the gem.
& gt Must have a certificate: Because many opal stones on the market are split or sandwiched, it is always a thoughtful suggestion to buy gems with a certificate in order not to waste money and pave the way for future investment. It is always an essential step to ask jewelers to produce authoritative gem appraisal certificates, not only to prove the value to insurance companies or resell them, but also to clarify the responsibilities of both parties.