Fire Opal

megalodon

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Fire opal is a translucent opal with colors ranging from yellow to orange to gold. Although it doesn’t show any color play, sometimes it exhibits bright green flashes. The most common variety are called Mexican fire opals found in Querétaro in Mexico. The fire opals that don't display color play are called jelly opals. The Mexican water opal is a colorless opal that exhibits either a bluish or golden internal shine. Opal is Australia’s largest gemstone. The Fire opal is soft with a Mohs hardness of 5.5 to 6, which makes it vulnerable to scratches by usual objects. It also has low tenacity which makes it easy to break. So, it has to be protected from abrasion and impact to avoid any damage.

How is Fire Opal formed?
Opal is a hydrated amorphous type of silica (SiO2·nH2O) with its water content differing by weight from 3 to 21% (typically between 6 and 10%). It is a mineraloid due to its amorphous nature, unlike minerals which are crystalline types of silica. It is deposited at a low temperature and can occur in nearly any rock fissures. It is usually found in limonite, sandstone, rhyolite, marl, and basalt.

There are two broad opal classes: precious and normal. The precious opals are defined by the property, Play of color (iridescence). It is a pseudochromatic optical effect resulting in bursts of colored light from certain minerals as they are converted into white light. The internal structure of precious opals allows it to diffract light, resulting in play of color. Opal may be clear, translucent or opaque depending on the conditions under which it was formed.

Where is Fire Opal found?
Mexico has been the primary source of fire opal in the world since a century. Fire Opal is found in Queretaro, Hidalgo, Guerrero, Michoacan, Julisio, Chihuahua and San Luis Potosi states of Mexico. Small fire opal pebbles can be found in silica-rich lava flows. Smaller quantities of fire opal are produced in Australia, Brazil, Honduras, Guatemala, United States, Nevada and Oregon.

Is Fire Opal valuable?
Fire opal is a mineral opal variety available in red, orange and yellow colors. The value of fire opal is based on its quality. There are many factors which define the quality like visibility, clarity, complexity and brightness of its color etc. The color is also a major factor in deciding its value. The price of red fire opal is usually higher than that of yellow ones.

Why is opal so expensive?
The price of opal will be defined based on the regular parameters of quality of the gemstones. The average price per carat of opals is defined by its color, direction of color, pattern, brightness etc.
 

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