It depends.... when they have just been dug out of the round they are extremely rough and vary in shapes. Once they have been polished they are very smooth and usually a round shape.
Opal is an amorphous mineral, which means it lacks a true crystal structure. It typically exhibits a smooth, glassy texture. Opal can also display a unique play-of-color caused by the diffraction of light, giving it a vibrant and iridescent appearance.
Opal is typically extracted from the earth through open-cut mining or underground mining methods. Miners use heavy machinery to remove overburden and dig into the opal-bearing layers, where they extract the opal-bearing rocks. These rocks are then processed to extract the opal gemstones.
The most expensive opal ever recorded is the "Olympic Australis," a rare black opal found in Australia. It was valued at around $2.5 million and weighs approximately 17,000 carats. This opal is known for its stunning play of color and rarity.
No. As it is synthetic it is man-made. A mineral must be naturally occurring and have a crystalline structure (among other requirements). Synthetic opal does not meet these criteria.
SiO2 .nH2O
Opal is an amorphous mineral, which means it lacks a true crystal structure. It typically exhibits a smooth, glassy texture. Opal can also display a unique play-of-color caused by the diffraction of light, giving it a vibrant and iridescent appearance.
The types of Opal that i am familiar with are White Opal, Fire Opal, Boulder Opal, Black Opal, Crystal Opal, Light Opal, Doublet Opal, Triplet Opal, Common Opal, Synthetic Opal, and Immitation Opal.
There are 5 basic types of opal. These types are Peruvian Opal, Fire Opal, Girasol Opal, Common opal and Precious Opal.
Another name for opal is "fire opal."
The fracture of an opal can be hard or smooth , An opal can have as many fractures as any other mineral can . Sometimes opal can be smooth , sometimes they can be hard . The fracture of an opal is hard and smooth .
India Opal Buloni (Opal) The Preacher (Opal's father) Winn-Dixie (Opal's dog)
Boulder opal is distinct from black opal in the following ways: * Boulder opal is usually mined in open-cut operations while black opal is mined in shafts. * Boulder opal is found in ironstone boulders, while black opal is found in seams.
black and opal
depens on the opal
Depends on what kind of opal
The Opal was created in 1851.
The Opal ended in 1860.