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Opals are made of silica and water, with water molecules embedded in them, producing unique optical effects. Because opals contain a variety of unique colors (black, white, pink, green, orange, red, blue, etc.), and with colorful light spots, opal jewelry is loved by many. The hardness of opal is between 5.5 and 6.5, and the texture is relatively fragile, usually showing a glass-like luster. In this article, we will discover what kinds of opal there are.
Classification of Opal
opal is divided into many types because of the different colors, and these types can be divided into two categories, that is, precious opal and common opal. Below we will describe the two categories in detail and which opals are included.
Precious Opal
Precious opal is highly prized for their unique optical properties. This type of opal is characterized by a metachromatic effect, that is, in different angles of light will show a variety of flashing colors. The following are some of the opal types included in precious opal:
White Opal
White opal refers to the opal with a white or light background color and an obvious color-changing effect. It’s famous for its milky background color and light spots with different angles, and is widely welcomed by the jewelry market. White opal is considered one of the most classic opal because of its pure and soft tone and rich color changes, and its milky background color makes the discoloration effect of light spots more prominent. White opal is usually translucent, and the high transparency of white opal is more precious. This opal is mainly produced in Australia, but a small amount of high-quality opal is also produced in the United States and Brazil.
Black Opal
Black opals are a class of opals with a black or dark color such as dark blue, dark green or dark gray, and have the same obvious spot change effect as white opals. The black background makes the change of color of the spot more obvious, and this effect is also the most prominent feature of black opal. Black opal is usually translucent or opaque, and black opal with high transparency has a more obvious light spot change effect, so it is also more precious. The darker the black opal, the purer it is and the higher its value. Black opal is also mainly produced in Australia, and in recent years some of the best black opal has also come from Ethiopia.
Boulder Opal
Boulder opal, also known as iron stone, refers to the Opal found in the natural iron ore matrix. This opal combines both the photochromic effect of Opal and the natural texture of iron ore. This symbiotic structure gives Boulder opal its unique beauty. The background color of Boulder opal is generally dark iron stone, and the color of the spot is usually red, green, blue, yellow and purple, and the species is very rich. Boulder opal is usually translucent, and the better the thickness of the Opal layer matches the texture of the substrate, the higher the value. The main source of this opal is Australia.
Crystal Opal
From the name of crystal opal, we know that this opal is more transparent as crystal, and in fact it is. Crystal opal is the most transparent of all opal species and is known for its clear appearance and multi-colored spot color variations. The semi-transparency or high transparency of Crystal opal makes the color change of the spot more obvious and charming, and the visual impact is particularly strong. Its background color is white, light or even colorless, and due to its transparent nature, the background color changes little to the color of the spot. Crystal opal is also mainly produced in Australia, Mexico and Ethiopia.
Fire Opal
Fire opal refers to an opal with an orange, red, or yellow base color, the more saturated the color, the higher the value. The fire opal gets its name because the colors look like burning flames. Fire opals show relatively weak spot color changes due to the bright background color, but most fire opals are characterized by their own uniform color. Mexico is the most famous source of fire Opal, especially in the states of Jalisco and Queretaro. Small quantities of fire opal are also produced in Australia and the United States.
Common Opal
Common opal is a member of the opal family that, unlike your opal, usually does not have a noticeable color-changing effect, but its variety of colors and uniform texture still hold a place in the jewelry and ornament market.
Milky Opal
Milky opal’s base color is white or cream, and it has a warm color that can highlight the color change of light spots. It is a classic type of opal. This kind of opal is usually translucent to opaque, and the transparent milky opal is more valuable. Milky opal is mainly produced in Australia, particularly in the Coober Pedy region, which is one of the most famous Opal producing areas in the world. A handful of other milky Opals are made in Brazil, the United States and Ethiopia.
Wood Opal
Wood opal is formed in the fossil of ancient trees, this Opal retains the structure and texture of the original tree, combining the natural beauty of the wood grain and the light spot discoloration effect of Opal, which is favored in the collection market. It’s widely used in the jewelry market mainly because of wood opal’s historical and visual uniqueness. Wood opal has a color of red, blue, yellow, green and purple, and the state is between translucent and opaque, and the wood opal with high transparency has a higher value. This opal is mainly produced in the United States, but some are also produced in Australia and Indonesia.
Jelly Opal
Jelly opal, also known as water opal, is found mainly in volcanic areas, where it is formed by the deposition of magma from volcanic eruptions after a chemical reaction with silica-rich groundwater. Jelly opal is translucent with a soft, waxy surface that exhibits an ethereal quality when light passes through it, usually with a milky white or light blue hue. Sources of this opal include Ethiopia, Australia and the United States.
Factors Affecting the Value of Opal
The value of opal is mainly affected by these factors: spot discoloration effect, transparency, background color purity, size and weight as well as cut and shape, in addition, the rarity of the origin is also one of the factors affecting the value of opal. If an opal spot discoloration variety, high transparency, clear background color can better highlight the spot discoloration effect, no excess cracks or flaws, then the value of this opal stone will be particularly high, and even by some collectors. In addition, if the opal itself is of excellent quality, the size and weight are also large, and the cut also maximizes the color and light spot changes of the opal, then this opal will become a gem that many people want to have.
Conclusion
Before summarizing the different types of opal, let us once again emphasize the diversity and charm of opal. From fire opal to black opal to precious crystal Opal, each type reveals the magical beauty of nature. Whether used for jewelry design or collection, each opal is unique and fascinating. Their color-changing effect, transparency and texture are masterpieces of nature and carry rich historical and cultural significance. Therefore, whether you are a jewelry lover, a collector or someone who simply appreciates the beauty of nature, opal deserves your attention and appreciation.