Figuring out uncooked opal is an important step in assessing its high quality and worth. Opal is a hydrated silica mineral that displays a novel play-of-color, or iridescence, when seen from totally different angles. This phenomenon is brought on by the diffraction of sunshine throughout the opal’s inner construction. Uncooked opal is usually discovered within the type of nodules or plenty, and it will possibly range in shade from white to black. Essentially the most precious opals are those who exhibit a vivid and intense play-of-color.
There are a couple of key traits that may provide help to to establish uncooked opal. First, opal is a comparatively mushy mineral, with a hardness of 5.5 to six.5 on the Mohs scale. Which means it may be simply scratched with a knife or different sharp object. Second, opal is a translucent to opaque mineral, that means that it permits some gentle to go by means of it, however it’s not utterly clear. Third, opal has a conchoidal fracture, that means that it breaks with a curved, shell-like floor.
