Synthetics 101 | All about Lab Grown Gemstones

so there's a lot of debate around natural gemstones versus those synthesized in a lab today we want to go over the key differences between the two types of stones as well as shed some light on the history of synthetics and the modern techniques used to produce them let's pull back the curtain so what's the real difference between a natural and a synthetic gem a natural gem is exactly how it sounds formed entirely by nature and without human intervention or modification aside maybe from polishing or fastening that's it it's just a plain vanilla gemstone how about a synthetic this term is used very specifically in gemology it's not a simulant which is an imitator of a different gemstone it's not a fake gemstone it is the artificial counterpart to a real naturally occurring mineral the synthetic has the exact same chemical physical and structural properties as its natural form some gemstones are more difficult to synthesize than others and not all stones are commercially viable to attempt to synthesize the most common synthetic seen on the market today are Ruby Sapphire emerald and spinel with diamonds to a lesser extent but of equal importance now let's take a look at how they're made for Ruby and Sapphire the process is the same since they're the same variety of gemstone corundum you take your base corundum ingredients aluminum oxide powder which produces synthetic white sapphire and add coloring agents to get the red or blue you desire the primary method for synthesizing Ruby and Sapphire is called the vernoy flame Fusion process named after the man who first synthesized Ruby in 1902 it was the first commercial process used and it's still very important today due to its low production cost and high growth rate other stones made with this process are spinel rutil and strontium Titanite so you take your powder of the right components to create whichever Stone you're going for and pass it down through an extremely hot oxyhydrogen flame which for corundum needs about 2 000 degrees Celsius or over 3 600 Fahrenheit this melts the ingredients which drop onto a plate and solidifies into a single Crystal called a Bool this process takes a few hours and yields a crystal with the same refractive index and specific gravity of the natural version you may be thinking that even though the ingredients are the same as a natural stone it's not forming in the same way as a natural stone and in much shorter time surely this will yield some differences right it does but they're subtle you need at least a 10x Loop to detect most of these differences for one air bubbles could have gotten trapped inside the pool during the formation process this tends to be seen more in older vernoi synthetics and is mostly absent in the modern synthetics these bubbles are very small and without stronger magnification can actually appear as Tiny dots rather than obvious Pockets but they still stand out because of the difference in RI between the gas and the Crystal secondly in a gemstone cut from a pool you may see parallel curved lines or color bands resulting from the formation of the pool these can only be seen from certain angles though and in lighter colored stones like a yellow Sapphire for example they may be nearly impossible to spot you can also get chatter marks which are a fire like or a crack-like pattern seen on the surface of a faceted synthetic stone that has been polished with insufficient care all synthetic spinel is made with this same vernoy process but the distinguishing features are different than those of corundum the chemical and physical properties of synthetic spinel are actually slightly different from natural spinel but it's still considered a synthetic the refractive index of a natural spinel is 1.718 whereas the ri of a synthetic spinel is about 1.727 too much aluminum oxide in a spinel induces stress in the crystal structure of the stone which can be seen as hazy patchiness using a polarized lens gas bubbles are also possible in synthetic spinel but they tend to be more complex in shape than corundum bubbles the vernoy flame Fusion process hasn't worked for emeralds so different methods to synthesize it are used including one called flux melt growth which is also used to make synthetic Alexandrite Emerald was the first stone synthesized with the flux melt growth process in a heat tolerant Crucible like graphite or platinum the gem ingredients are dissolved in a molten fluid or flux where it recrystallizes to form the desired gem material using this method crystals can take two months or up to a year to grow depending on the size you want this makes it more costly than the vernoy method but corundum can also be synthesized in this way some of the things to look for in a flux melt Emerald are tiny platelet inclusions from The Crucible itself you can also find veils of feather-like inclusions and sometimes small cavities filled with flux will occur as well another synthesizing technique is hydrothermal growth which attempts to imitate the natural process that creates many natural gemstones mineral-rich water under high heat and pressure can cause gems to crystallize over time so to replicate that the required gym materials are sealed in a container of water and it's essentially pressure cooked steam can't escape and the water is heated Beyond its boiling point this allows materials that are normally insoluble to be dissolved quartz can also be made in this way Emerald requires temperatures of 600 Celsius and 1 000 times atmospheric pressure and grows about a third of a millimeter a day for two weeks since the container is under tremendous pressure and sealed up you can't add more material to it during the process if you want a larger Stone you can start with a seed gem from a previous batch and the new material will crystallize on it the traits of hydrothermal Emerald are similar to flux melt Emerald there can be wispy Veil inclusions and metal inclusions from the container both also appear bright red under a Chelsea filter but so do some Colombian emeralds so this test isn't conclusive lastly let's talk about lab-grown Diamond the first ones created in 1953 were small and used for industrial purposes gem quality crystals wouldn't be produced for many years there are three different utilizations of hpht or high pressure high temperature synthesization the belt press the cubic press and the bars method which claims to be the most compact and economical though all have their advantages and they all generate ridiculous heat and pressure another newer method of diamond synthesis is chemical vapor depth position or cvd which uses hydrocarbon gas it's simpler and more flexible than hpht and it doesn't require the Heat or the pressure to put it simply a gas cocktail with some sort of carbon source is pumped into a chamber where it crystallizes onto a waiting substrate that will allow the diamond to form with the right structure the result is a wide flat disc of diamond the world's most expensive coaster usually lab equipment is required to determine if a diamond is natural or lab grown things to look for are color zoning called hourglass or Maltese cross zoning they also react more strongly to shortwave UV light than long wave which is the opposite reaction of natural diamond you can also have little breadcrumb inclusions of dissolved metal and dust these tiny metal inclusions can also cause lab-grown diamonds to be attracted by strong magnets however as lab grown diamonds increase in quality these inclusions appear less and less sometimes indicative of an older diamond the quality of synthesized gemstones is improving every year and they are very difficult to tell apart from their natural counterparts hopefully today you learned a little something about synthetic versus natural stones with all that said are you team natural or team synthetic let us know down in the comments and don't forget to like And subscribe and of course ring that Bell so you don't miss out on our future videos thanks for watching [Music] [Music]

Channel: Gemstones

Views: 89,055

Keywords: jtv, jewelry, jewelry television, gemstones, gems, gravel butter dubai, synthetic, synthetic gemstones, synthetic diamond, lab grown, lab grown diamond, lab grown vs natural, natural diamond, natural gemstones, sapphire, ruby, emerald, synthetic emerald, lab grown emerald, spinel, diamond, corrundum, lab grown gemstones, science, rock science, gem science, fun science, gemologist, lab, synthesize, white sapphire, aluminum oxide, Vernueil, boule, faceted, faceted gemstones, gemology

Id: kUXYBKPy55E

Length: 8min 11sec (491 seconds)

Published: Thu Feb 09 2023