More often than not whilst “nerding-out” amongst other glass otaku do I find myself in the age old argument of “Synthetic Opals vs. Real Opals”. Without any knowledge on the subject I often just sit back and let the argument go on, but now after having enough I’ve decided to read up on the subject, and in turn share my findings with you. Let’s move on shall we?
“Tumbled Opals”
If you crack open an encyclopedia or better yet, Wikipedia and look up Opals you will find that it is their basic composition which gives them the properties needed for encasement in glass. Like glass Opal is an amorphous form of silica meaning that it lacks the long-range properties of a crystal. What makes amorphous solids different is that they have properties which when heated effect the matter in different ways, to put it simply this is why when glass is heated it becomes more liquidous. Thus with opal being formed of silicate much like glass has the ability to be cased within molten glass. Opals also have the unique ability to reflect every color in the visible spectrum, making them a sight to behold… especially on a beautiful glass pipe, pendant, or marble.
“Thank You” By Daisuke Saito
Often times people sneer at even the idea of synthetic opals, thanks to companies like Whole Foods and others trying to shove the whole “Organic Movement” down society’s throats people often believe across the board that natural is always better than synthetic. What we found is that this is not the case, The synthetic began with the discovery of the ordered sphere structure of precious opal which led to its synthesis by Pierre Gilson in 1974. The resulting material is distinguishable from natural opal by its regularity; under magnification, the patches of color are seen to be arranged in a “lizard skin” or “chicken wire” pattern. Furthermore, synthetic opals do not fluoresce under UV light. Synthetics are also generally lower in density and are often highly porous. Since Pierre’s breakthrough he has turned the creation of synthetic opal to an art form. Through his company Gilson Opal he and his team create the worlds premiere synthetic opals for jewlers, lapidary artists and of course, glassblowers.
Gilson Synthesized Opals!
Gilson Opals are the easiest to encase in glass due to their porus nature and their “crystaline” structure, making them less perceptible of damage when putting them under high-temperatures. Also since they are scientifically manufactured in a laboratory Gilson offers a brilliant array of colors and options of stone-shape. You can buy Gilson Opals in cuts just like a gemstone, ones like:
- Ovals
- Pears
- Rounds
- Trillions
- Hearts
- Squares
- Marquis
- Spheres
- Cubes
- Faceted
- Tumbled Opals – Meaning that they are tumbled for over 8 weeks thus removing all the gritty surfaces and other rough spots generally found on opal chips.
- Rough Opals
- Chips
- Chards
- Powder
Natural opals on the other hand are a bit more tircky to encase. This is because of their lack of a cyrstaline-like sturcture along with other natural impurities that may have formed over time. Due to this lack of a formalized molecular structure natural opal is very difficult to encase because it is not as heat resistant as synthetic opal. Their advantages lie in that their shaping is much more unique as well as the fact they flouresce under UV light. “Precious” opal, which isĀ is also rare and can be quite expensive making products like Gilson more enticing to glass artisans.
“The Galaxy Opal” The Largest Precious Boulder Opal Ever Discovered
Opals naturally come in a variety of different colors from white, black, boulder opals, clear hydrophane opals and finally crystal opals, but more commonly (natural and synthesized) they come in either black, white, and crystal. As far as color goes, its personal preference. Many people perfer black over white or crystal when glassblowing. All colors work the same in the glass. The darker colors reflect wonderfully and stand out alot. White or crystal blend into the glass and look wonderful in jewelry and sculpture.
All in all we are amazed by the opal, it’s glimmering colors make us entranced every time we look at them. So the next time you find yourself in an argument with some fellow otaku over opals, don’t be hesitant to use this as a quick reference.
One Response to “An Enthusiasts Guide to Opals”










Beautiful article! as beautiful as the opals themselves, synthetic or earth natural! thank you!