Mad About Science: Artificial crystals and gems

By Brenden Bobby
Reader Columnist

This week’s topic, suggested by our local library director, Ann Nichols, focuses — so to speak — on one of the most important yet often overlooked items in our daily lives. Artificial crystals and gems allow our computers to function, provide immense amounts of electrical power in solar voltaic panels and they just look generally pretty. Who hasn’t seen the interior of a geode and thought to themselves, “Wow, how did nature do that?”

Nature isn’t the only one responsible for the production of impressive crystals. Human beings need crystals to maintain our 21st-century lifestyle, and we can’t wait around for millions of years for nature to make them all for us.

A semiconductor. Courtesy photo.

Despite how many synthetic gemstones you might see on home shopping channels, the bulk of human crystal production is actually centered on the electronics industry — primarily in the production of microchips and lasers.

Crystals in laser technology are employed for a number of complicated roles, but their primary function is to help focus light into a beam with the help of ions mixed into the crystal’s structure. This is an insanely complicated subject for my little brain, so go ask a librarian if you want the nuts and bolts of how crystals work in lasers.

Synthetic crystals are employed in a range of electronic functions, from oscillators to semiconductors. An oscillator is designed to vibrate at a very precise frequency when an electrical charge or field is introduced, allowing the transmission of information through the air. Some forms of WiFi use crystal oscillators and receivers, as do a number of radio systems developed around 1900. A semiconductor is a substance that’s halfway between an insulator, which doesn’t allow electrons to freely move through its structure, and a conductor, such as copper wire that allows electricity to move through it effectively. 

The purpose of a semiconductor is to regulate the amount of electricity that flows through a particular structure in order to avoid overloaded circuits or other dangerous situations. Tiny quartz crystal structures make effective semiconductors and oscillators, and are relatively easy for humans to create.

I’m sure every electrician and computer engineer in Sandpoint is laughing at my explanations right now. I invite you to share your knowledge and experience in this field.

Meanwhile, scientists have developed a number of ways to synthesize crystals.

One method is called crystal pulling, or the Czochralski process. This method is achieved by filling a crucible — essentially a miniaturized enclosed forge — with a desired chemical substance. In the case of garnets, this substance would be a mixture of yttrium, iron and oxygen. If the diamonds were to be colored, other substances would be introduced into the mix. This chemical concoction is heated in the crucible to more than 2,500 degrees Fahrenheit and then a seed crystal is dipped into the mix.

The purpose of a seed crystal is to encourage the mixture in the crucible to replicate the crystal lattice structure of the seed, creating a uniform and predictable crystal. As the crystal begins to form, the seed is pulled away by a rigging equipped with magnets.

We aren’t entirely sure why a seed crystal needs to be employed, but it reliably encourages the growth of new crystals, whereas under normal conditions, it would take a very, very long time under sustained heat and pressure to begin forming the crystals without a seed.

Another form of crystal creation is called flame fusion. Aside from being a great band name, flame fusion is one of the most cost-effective means to produce synthetic gemstones. This method drops chemical powders through high-temperature flames and allows the substance to fall onto a seed crystal, effectively building the crystal upward.

Synthetic diamonds are formed by a number of different processes. One way is to use vacuum chambers to replicate the conditions deep beneath the Earth’s crust billions of years ago, by applying tremendous heat and pressure to carbon atoms to force them to create clean and uniform lattices. Another process called chemical vapor deposition also uses a vacuum chamber to control carbon atoms — however, rather than crushing them into uniformity, the vacuum chamber allows the carbon atoms to fall onto seed plates and grow.

It wouldn’t be an article about gems if we didn’t talk about color, and synthetic gems are capable of producing dazzling hues that don’t occur in nature. Natural garnets are red because of the presence of iron in their chemical makeup. Some artificial gems have arrays of metal flecks scattered through them during the growing process — a gem infused with copper may be reflective and have an amber color. Others like artificial cat’s eye opals have specialized gas solutions introduced and trapped inside the gem during the growth process.

The final type of artificial crystal I’ll share has been created by humans and most other animals for tens of millions of years, if not longer. Our urine is filled with all sorts of chemicals, including salt, which can act as a crystal seed when introduced to other chemicals in our urinary tract. 

Calcium can build up in our kidneys and form crystals, which can break off and exit painfully in the form of kidney stones. Cholesterol can also form crystals that leave our body through our urine. Our “No. 1” excretion can actually contain as many as 13 different types of crystals, all formed inside of our body.

While calling these artificial might be a stretch, they are certainly man-made.

Stay curious, 7B.