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Can you GROW an Opal?

The Thought Emporium・28 minutes read

Opal, a unique gemstone made of silica, displays a play of color and is highly valued based on its quality, with black opals in particular fetching high prices. Synthetic opals replicate natural opals through precise control of particle sizes and stacking, with the color display explained by structural color phenomena and Bragg diffraction.

Insights

  • Opal, a unique gemstone, is prized for its play of color and can fetch high prices based on quality, with black opals particularly valued for their dark backgrounds that enhance color flashes.
  • Synthetic opals, mimicking natural ones through precise particle control and stacking, rely on nanostructures to create color effects, akin to biological materials like viruses and butterfly wings, with potential applications beyond jewelry in holograms, embossed holograms, and energy storage.

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Recent questions

  • What makes opal unique among gemstones?

    Opal is distinct as it is not a crystalline mineral like diamond or ruby but is composed of silica, showcasing a play of color that changes when viewed from different angles.

  • How are synthetic opals created?

    Synthetic opals are produced by creating silicon nanoparticles of specific sizes using chemicals like water, ethanol, ammonia, and tetraethyl orthosilicate (TEOS) through the Stöber process, mimicking the structure of natural opals.

  • What determines the color of synthetic opals?

    The color of synthetic opals is determined by the sizes of the particles used in their creation, with larger particles resulting in redder hues, while the stacking and spacing of particles influence the play of color in the final opal.

  • What other materials exhibit structural color phenomena?

    Apart from opals, certain viruses, bacteria, and butterfly wings also display structural color phenomena, deriving their color from nanostructures rather than traditional pigments.

  • How are opals dried industrially without cracking?

    Opals are dried industrially using supercritical drying at 10,000 psi and 300 degrees to prevent cracking, ensuring the synthetic opals maintain their structural integrity.

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Summary

00:00

Creating Synthetic Opals: Mimicking Nature's Beauty

  • Opal is unique among gemstones, not being a crystalline mineral like diamond or ruby, but made of silica and exhibiting play of color, changing hues as viewed from different angles.
  • Black opal is highly prized for its dark background enhancing color flashes, with opals graded based on the quality of play of color and pattern, some fetching thousands of dollars per carat.
  • Opals vary based on their origin, with opals from places like Cooper Pedy in Australia being highly valued for their quality and fetching high prices.
  • Synthetic opals can closely resemble natural opals, being cheaper to produce, with the process involving creating silicon nanoparticles of specific sizes and stacking them correctly to mimic natural opal's structure.
  • The process of creating synthetic opals involves using chemicals like water, ethanol, ammonia, and tetraethyl orthosilicate (TEOS) to form silicon nanoparticles of uniform sizes through the Stöber process.
  • Particle sizes determine the color of synthetic opals, with larger particles producing redder hues, and the stacking of particles affects the play of color in the final opal.
  • Structural color and Bragg diffraction explain the color display in synthetic opals, with the particles' spacing interacting with light waves to create specific colors when dried out.
  • Synthetic opals mimic natural opals' play of color by allowing particles to settle in a pseudo-crystal pattern, creating distinct grains with varying spacing and orientations for color variation.
  • Other natural and biological materials, like certain viruses, bacteria, and butterfly wings, exhibit structural color phenomena, deriving color from nanostructures rather than pigments.
  • The process of creating synthetic opals involves precise control of particle sizes, stacking, and settling to replicate the unique play of color seen in natural opals.

13:02

Creating Colorful Opal Holograms with Nanostructures

  • Embossed holograms work on a similar principle to slices of meat where cells align to give an opal-like sheen.
  • The colorful effect in holograms is due to a nanostructure on plastic, transferable to items like chocolate.
  • Inverse opal, made with polystyrene particles, has applications in energy storage and electrodes.
  • Opal creation involves centrifuging a solution at 3500 rpm for an hour or two to form a pre-opal pellet.
  • Opal color comes from nanostructure, not particle color; different particle colors yield varied opal hues.
  • Longer settling times produce opals with distinct color areas and a play of bright colors.
  • Commercially, opals are made in tall tanks with dilute particle solutions, settling over 7 months.
  • Opal pattern forms in weeks, but a 7-month settling time is crucial for pattern preservation.
  • Supercritical drying at 10,000 psi and 300 degrees is used industrially to dry opals without cracking.
  • Synthetic opal can be strengthened by fusing particles at 800 degrees or filling gaps with silica or resin.

25:25

Future projects and updates for supporters.

  • The text mentions the possibility of creating a drying chamber in the future, with plans to add sapphires, diamonds, and other projects to the list. It encourages viewers to subscribe for updates and provides links for more information. The text expresses gratitude to supporters who contribute to making these projects possible, including patrons, channel members, and supporters on Kofi, who also gain access to a supporter discord. It suggests following the creator on social media to stay updated on projects before they are featured in videos.
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