Natural opals have a kaleidoscopic play of colors that are unlike synthetic ones. Synthetic opals are created in a lab. Dead spots and the size of the spheres are some of the factors that affect the value of a double fire opal.
Natural opals have a kaleidoscopic play-of-color
Natural opals exhibit a kaleidoscopic play-of color because of their composition of uniformly sized sub-microscopic spheres of silica. As white light passes through the spheres, it is absorbed, splits and re-emits in different colors. The resulting play-of-color is dependent on the size of the spheres, which range from 0.1 to 0.2 microns in diameter.
Although common opals also have silica particles, they lack the kaleidoscopic play-of-color that makes natural opals so desirable. The silica particles are randomly arranged in different shapes, with irregularly sized gaps between them. As a result, the color does not diffuse, but is absorbed instead. Scientists believe that this irregularity is the result of differences in water evaporation rates.
Opals can be classified by color and transparency. Some are transparent or translucent while others have a black background. Opals with a black background have the most colorful play-of-color. These are often rare and very sought-after.
Synthetic opals are created in a lab
Synthetic opals are a close match to natural opals. These stones have the same crystalline structure, but are much more durable, as the production process allows them to grow in a controlled environment. In addition, these gemstones are a great deal less expensive than their natural counterparts. They can also be worn every day without the worry of breaking or cracking.
A synthetic opal is created by adding resin to a natural opal. The resin impregnated synthetic opal has a lower specific gravity than its natural counterpart, and is usually much more uniform in size. It is important to understand how these stones are created before buying one.
Dead spots affect opal value
Opal's value is affected by a number of factors. One of these factors is whether the gem has dead spots. These spots are areas of the gem where the play of color has been lost. When this happens, the only color seen is the background. This lowers the value of the stone.
The play-of-color range and strength are another important factor in determining opal value. Not all precious opals will show every color in the rainbow. This is a function of the diffraction of light, which affects the color spectrum. Usually, red is the most prominent color, followed by green and orange. However, these preferences are not fixed and can change from time to time.
Other factors affecting white opal with fire value are the presence of fractures, pits, and other defects. Opal also contains a matrix, which affects its value. It is also vulnerable to crazing, which is caused by exposure to bright lights. This is one of the reasons why it is important to keep your opals out of direct sunlight.
Size of the spheres affects opal's value
Opals come in a variety of colours. The color of an opal depends on the size of its spheres and how the light is reflected. Smaller spheres tend to be bluer than larger ones. Generally, larger spheres have red or orange colours.
The water content of an opal is a key factor that affects its value. The higher the water content in an opal, the less stable it is. Several methods have been used to study the water content of opal samples. All of these methods indicate that the water in an opal is in a molecular form, either adsorbed or free water molecules.
Opal is also valued for its play of colors. These colors are caused by diffraction of white light through the silica spheres. As the light passes through the stones, it produces a spectrum of brilliant colors. The red and fire opals are more valuable than the blue ones. This is due to their smaller spheres.
Opticon
One way to tell if your opal is of high quality is to see if it has an Opticon coating. Opticon is a clear epoxy resin that fills in surface-reaching fractures. After the resin is applied to the stone, it solidifies. Unlike nail polish, Opticon doesn't alter the color of the gemstone, and it also protects it from further damage. However, some people do not like the treatment, and it's only a permanent solution for minor fractures.
Before using the Opticon, clean the cabochons using acetone. After the cabochons are cleaned, pour the Opticon resin over them. You should be able to feel the resin soaking into the cabochons. Once the cabochons are completely soaked, place them in a 1-pint Mason jar with a lid that seals well. Fill the jar with warm water and simmer for 1 hour. Buy gemstones online from Ratanrashi.