photo: A closeup view of a "diamond window" extra facet on an Arkansas quartz crystal point from Montgomery County. This is basically an extra facet caused by twinning defects in the atomic lattice of the quartz.
Alternately, untwinned crystals that were "eye-clear" were used during WW2 for crystal radio frequency oscillators. The quartz points were mined extensively in Arkansas during this period of wartime (after initial Brazilian sources of the quartz were cut off by opposing submarines, and the US military turned to the Ouachita Mountains for its at-home source of this vital resource). After mining, the points were then cut into quartz crystal oscillator wafers that were used in the war effort for the United States military's proprietary radio frequency control (quartz is now lab grown to reach absolute pinnacle perfection standards for use in various fields of technology).
Quartz vibrates at a specific frequency when electricity is introduced. It was important though that the quartz being cut into wafers was free of imperfections. Every piece of quartz was examined by oil-submersion/ polarized light techniques and then they were marked according to their quality. Then, polarized light was used again to determine and mark the location /orientation of the optic axis. Twinning was seen often during this stage, and it was a technical imperfection in the atomic lattice that had to be discovered, marked, and avoided when the wafers were cut. If twinned regions were missed during this stage, they were discovered after etching the cut wafers with acid, and if found, marked out with a pencil so that they could be avoided when cutting the final oscillator wafer. Untwinned crystals are rare, as most quartz found in nature is twinned in some way. After the wafers were cut, and fine tuned to varying sizes, they were classified and tested, with thinner wafers exhibiting a higher frequency, and the thicker wafers a lower frequency. The fine tuning stage at the end occurred after a final soak in solutions of acid, neutralizing agent, water, and then an end stage delicate cleaning by a specialist team known as "the millionth of an inch girls". If any of the wafers were cut/etched in too high of a frequency, a special technique reversed this using x rays to "influence" the quartz atomically to lower the frequency back down.
I would be curious to further understand the influence that natural radiation has had on the other various atomically associated properties of quartz (ie certain smoky quartz varieties that have been exposed to various natural sources of radiation over long periods of time underground). Perhaps with the advance of quantum technologies (strategically paired with compartmentalized ai systems) we will be able to discover new incredible properties hidden within the atomic lattice of quartz, laying a path to uncharted frontiers for future technologies/ proprietary applications of this amazing mineral.
On a side note, applying mechanical pressure to quartz releases an electrical charge. If enough pressure is put onto pure quartz, it will excite the electrons within the quartz and they will light up briefly like a light bulb. This can be tested and seen in a dark room if you take two smooth pieces of quartz and rub them together.
photo by Arkansas Minerals LLC