Opal Looks Like It Has A Universe Inside It!
The unique play of colors in contraluz opal has led some people to believe that it looks like it has a universe inside it. This is because the colors of the stone can be so vivid and vibrant. When held up to a light source, the stone can appear to be filled with stars, galaxies, and nebulae.
Contraluz opal is a type of opal that is only found in the state of Jalisco, Mexico. It is characterized by its unique play of colors, which is only visible when the stone is held up to the light. The colors of contraluz opal can vary widely, but they often include red, orange, yellow, green, blue, and violet.
The name "contraluz" comes from the Spanish word for "backlighting." This is because the best way to see the play of colors in contraluz opal is to hold it up to a light source from behind. When this is done, the light is refracted through the stone, creating a dazzling display of color.
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| The Contraluz Opal Looks Like It Has A Universe Inside It. Photo: Bonhams |
The piece has a botryoidal opal formation which forms a unique inclusion.
The stone pictured above weighs approximately 119.0 carats and measures, and was found in Opal Butte, Oregon. Despite the beautiful swirling colors, what makes this piece really unique is the brown nebula-like cluster formed inside it.
Bonhams describes the stone with dimensions of 4.6cm x 4.4cm x 1cm. Bonhams also claims the stone is clear and transparent with a crystal body having a fine, firey play-of-color that has the quality of a gem. Lastly, the stone has a botryoidal jasper formation, forming an inclusion that is unique.
Opal
Opal is hydrous silica (SiO₂·nH₂O). Technically, opal is not a mineral because it lacks a crystalline structure. Opal is supposed to be called a mineraloid. Opal is made up of extremely tiny spheres (colloids) that can be seen with a scanning electron microscope (SEM).
A colloidal crystal is an ordered array of colloidal particles and fine grained materials analogous to a standard crystal whose repeating subunits are atoms or molecules. A natural example of this phenomenon can be found in the gem opal, where spheres of silica assume a close-packed locally periodic structure under moderate compression.
Gem-quality opal, or precious opal, has a wonderful rainbow play of colors (opalescence). This play of color is the result of light being diffracted by planes of voids between large areas of regularly packed, same-sized opal colloids. Different opalescent colors are produced by colloids of differing sizes.