Synthetic Quartz

Synthetic quartz


Most natural crystal quartz tries to form more than one crystal in the same space; a phenomenon known as Brazil Law Twinning, that becomes visible under crossed polars, and renders most natural material unsuitable for electronic applications.  But for a time, twinning was a tool gemologists could use to separate natural from the much purer synthetic quartz, through the observation of twinning lines ...at least it was useful until they began growing twinned crystals, making that tool obsolete, and confounding us once again.



The process of creating pure industrial synthetic quartz was perfected over the years, attracting the jewelry industry's attention; and of course it quickly become enamored with it, which promptly inspired someone to figure out how to expand the market by doping synthetic quartz with iron, amethyst's coloring element, which in turn caused the amethyst market to take a nosedive that it has still not recovered from to this day, and you don't need a turban or a crystal ball to see why it never will.  Colored quartz is favored for jewelry, and most of the amethyst and citrines now on the market are synthetic.


By their very definition, synthetics must possess all the same gemological properties as their natural counterparts, meaning synthetic quartz offers all the same gemological property data as shown above for natural, and only in rare cases will you come across a synthetic that possesses a property significantly different enough to indicate synthetic origin.  So while there are various methods for identifying synthetics, we're forced to accept the fact that there are 3 levels of synthetics out there:



1- those that are easily identifiable



2- those that require knowledge, skill and the use of equipment to identify



3- and those we haven't got a snowballs' chance in Hades of identifying!

And sadly, synthetic quartz generally falls into the latter category; which is why the price of amethyst tanked by at least half when a slew of synthetic amethyst was salted into parcels of naturals, and gemologists had no way of separating them.  And astonishingly, once amethyst prices tanked, gemologists were told 'not to worry' about not being able to separate them, because the price of amethyst was already so low!!

Now, pick your jaw up off the desk, and consider just how devastating a hit like that would have been to the entire industry if the same thing had happened when synthetic emerald, red beryl, ruby, sapphire, opal and aqua hit the market?!  Did a chill run up your spine?  I shudder to think!


But thankfully, that didn't happen despite the fact that those synthetics can also be made using the SAME hydrothermal process as synthetic quartz!  How can that be, you might ask?  Because those synthetics have visible cellular growth structure indicators that synthetic quartz doesn't have! ...are you scratching your head wondering how the heck can that be?


Easy!  Since industrial quartz had to be so pure for watch, radio and other electronic applications, they had no choice but to perfect the crystal growth process for quartz, and after so many years of practicing for industrialized use, eventually the technique for creating synthetic quartz reached the stage where there was NOTHING left to detect ...which is why I said you'd have a snowball's chance in Hades of separating synthetic quartz from natural; especially now that they also grow it in twinned crystals, relegating the use of Brazil Law Twinning as a diagnostic tool for separating natural from synthetic to the rubbish heap, and leaving inclusions as the sole means of separation.



Let's take a closer look at the hydrothermal quartz crystal growth process:



Bits of low quality milky quartz are placed in an alkali-rich water solution of melted silicon oxide which is super-heated in a gold-lined and pressurized autoclave, with vertically stacked heaters that are set with the bottom heaters much hotter than those at the top, and the milky quartz sinks to the bottom where it reaches the molten stage. 



A high quality colorless seed crystal hangs at the top of the mixture awaiting the heat differential between the top and bottom along with gravity to cause natural convection currents that send the molten quartz on its journey up and down, (much like blobs in lava lamps that rise and fall as the excessive heat at the bottom pushes currents upward), carrying the molten quartz material up toward the cooler temperatures where it cools just enough for some of it to precipitate out of the liquid state and adhere to the seed crystal before gravity takes over again, pulling it back down to the molten temperatures where it re-melts and the whole process begins again, repeating over and over until the solution is exhausted or the desired crystal size is reached in a matter of days or weeks.


With an entire synthetic amethyst crystal in hand, the original colorless seed plate the crystal grew on is discernable with back lighting when observed at the right angle, and sometimes breadcrumb inclusions are visible where tiny quartz crystals formed along a single plane near the seed crystal before being engulfed by the main crystal.  But once cut, the seed plate and such defects are cut away leaving no indication of synthetic origin other than a stone that looks TOO clean!  Our only hope of identifying synthetic quartz is if small breadcrumb inclusions that are usually thickest near the plane of the seed crystal, and may require a microscope to find, can be detected.  If they cannot be found we must assume that what we have is probably synthetic.



So let's just consider the issues surrounding synthetic quartz as facts we have to live with and move on with a closer look at the similarities and differences between the many members of the natural quartz family.  We'll begin with the crystalline, or macrocrystalline group:



Rock Crystal:  Thought to be 'frozen by the gods forever', the word "crystal" is derived from the Greek word "krystallos" meaning ice, and although rock crystal is very common, and can be found in enormous sizes reaching into the tons, little of it is worth much except in large, perfectly clear pieces that can be sculpted, such as the world's largest and finest perfect 107 pound Burmese sphere that measures 12¾ inches in diameter!  But most rock crystal is not suitable for cutting, and ends up being made into objects such as quartz votives, small figurines, etc. 


Rock crystal sculpted angel 

  

That said, in its finest and cleanest forms, rock crystal can be quite spectacular, such as the crystals found in the U.S. called 'Herkimer Diamonds' from Herkimer County in the Mohawk Valley of the Adirondack Mountains in New York state; the only place on earth where doubly terminated "crystal clear" quartz crystals are found.  Eons ago, a 50 mile long and 10 mile wide inland sea left pockets of dolomite limestone where beautiful free-form crystals grew detached from the rock, growing from the center out in all directions, and having no striations on the prism faces so when faceted they make fabulous diamond imitations; hence the name



Other commercially viable rock crystal known as 'Arkansas Diamonds' come from the Hot Springs Arkansas area in the U.S., and large scale rock crystal mining operations work the Mount Ida area of the Ouachita (wash-eh-taw) Mountains, but frequently the crystals are heavily stained with iron oxide which must be removed with acids before the beautiful crystals can be used as diamond substitutes.  Fine quality rock crystal is also found in Australia, Brazil, Burma, Canada, Japan, Madagascar and Switzerland.
But what the bulk of rock crystal generally lacks in beauty, it makes up for in intriguing inclusions that can be captivating to the eye, such as rutile, fully formed black tourmaline crystals, flecks of gold, pyrite, green clumps of chlorite, and many other fascinating things to look at that make it appealing as specimens, and quite suitable for costume jewelry.

Milky Quartz Crystal:  Distinguished from rock crystal by its white to grayish-white color from which it derives its name, the milkiness is thought to be caused by tiny cavities and microscopic CO2 gas bubbles or water that cause milky quartz to run the gamut from translucent to opaque; sometimes even in the same crystal.  Milky quartz is the most common form of quartz on the planet, penetrating various types of rock worldwide, and is visible as milky white veining that frequently contains specks of gold in between the layers of rock that it penetrated.

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