The α- Alpha and the β- Beta
The Science & Art of Quartz.
Our most beloved gemstone, in its myriad forms…. Eleven crystalline and 2 non-crystalline minerals comprise silica (SiO2), though Quartz is the most common form. In our landscapes, in our lives…
Twelve percent of Earth’s surface is quartz, and a full 20% of the whole crust is Quartz.
Geologists have plotted the various forms of SiO2 over the years, culminating in the diagram to the left.
My SiO2 interests these days, and most of my life actually, lie in the blue and pink areas on the diagram: α-quartz and β-quartz, respectively.
α-Alpha and β-beta quartz occur in all igneous, metamorphic and sedimentary rock types. Within the alpha and beta fields lie a seemingly vast array of different rock types, all of which comprise quartz.
Beautiful enough for gemstones. Revered since antiquity. The ancient Egyptians were gifted artisans whose use of blood-red Carnelian—one of the Quartz gemstones—is iconic and legendary.
It’s ALL Quartz…
Trace elements (e.g. iron) produce the colors we see in all forms of Quartz, though it is not color but size and translucency that are the keys to the Classification of Quartz.
From Large to Small…Macro to Micro to Crypto. Size matters not only in how Quartz gemstones are classified, but how they come to display the endless and gorgeous variation in color and patterns of spheres, bands and layers–whether smooth or crenulated. And why we love these humble stones more than diamonds.
Today, it’s all about Macro. Following are a few examples of the flavors of Quartz whose crystals are large enough to see without magnification. Tomorrow, the small stuff.
Macrocrystalline: Crystals are easily identified without magnification.
These Amethyst crystals are an example of Macrocrystalline Quartz.
The crystals do not have to be whole, perfect and complete like these. Some Quartz is quite coarsely crystalline yet doesn’t display the crystal habit of the mineral.
Rose Quartz is a type of Macrocrystalline Quartz that does not form crystal faces, but is composed of many intergrown crystal ‘sub-individuals’
Second most popular Quartz gemstone…Amethyst is first.
A naturally occurring variety of Macrocrystalline Quartz comprising zones of Amethyst intergrown with zones of Citrine.
Ametrine cut perpendicular to the c-axis of the crystal. Is that freaking cool or what???
Quartz crystal axes: 
Macro…Micro…Crytpo…it’s ALL Quartz.
Versatile, beautiful, ornamental
Carnelian Pendant wrapped in Copper wire.
(and yes, Carnelian is one of the many lovely flavors of quartz, of the Microcrystalline Quartz variety)
Coming Soon: Microcrystalline Quartz
References:
Ametrine https://www.mindat.org/min-7606.html
Ametrine https://en.wikipedia.org/wiki/Ametrine
The Mineral Citrine https://www.minerals.net/mineral/citrine.aspx
The Mineral Quartz https://www.minerals.net/mineral/quartz.aspx
The Quartz Page http://www.quartzpage.de/crs_intro.html
Mary C Simmons ... Art and Word 