August 31, 2021

Amazonite: a rare expression of a common mineral

This dreamy blue-green mineral belongs to the most common mineral group on Earth’s crust. But the way it catches your eye and captivates - with its elegant geometry and soul soothing opaque hues is anything but common.

We love it long time

Amazonite's adorned humans in Egypt since as early as 6000 BC and was widely used after 3000 BC. (Hmm, gotta wonder if humans' appreciation for and fascination with eye-catching minerals just may be innate...?)

Modern archaeologists found prehistoric amazonite quarries near the Red Sea in the Eastern Desert of Egypt! It was used to make beads, amulets and inlays waaay back then.

Today, you can find it tumbled & polished, rough, carved into towers, shaped into cabochons, formed into beads and faceted for jewelry. But it’s less common to find commercially available Amazonite specimens in their natural crystal shapes.

Shape

Single amazonite triclinic crystal forms are prismatic in habit. Triclinic crystals are defined by 3 axes of unequal lengths, none being perpendicular to another. A video'll help. Check it out here:

Oh Feldspar

Amazonite's a blue green variety of microcline, which is an alkali feldspar. And feldspars are the most common minerals on the planet. Here are some other feldspars you probably know and love: moonstone, labradorite, clevelandite, and adularia.

Those characteristic white lines

Small white lines (lamella) are observed on amazonite crystal faces. They're also called exsolution lines (or exsolution planes if you see them in 3D.)

As microcline crystallizes, incompatible compositional planes segregate out. This behavior is a type of twinning (polysynthetic twinning according to albite and perthite laws in case you're wondering). Twinning means intergrowth of crystals. They share the same crystal lattice.

Cleavage planes vs. crystal faces

Feldspars cleave. That means they break along planes of weakness within the crystal. These planes generally form somewhat smooth surfaces and may look like crystal faces.

You can tell if you're looking at a cleavage plane if its parallel to the exsolution planes. Also cleavage planes don't have those white exsolution lines on their surfaces, and they usually flash when moved about in the light (not like flashing at Mardi Gras - flashing like you see in labradorite).

The name microcline actually comes from a greek word meaning "little slanted". This refers to microcline's cleavage angle.

Here's another video to show you the difference. Watch out though, this one has sound...

World Class Specimens

Highly prized and sought after amazonite comes from Colorado. It’s known for its exquisite shaped crystals, bold blue-green color. But the aesthetic (and price) really goes up when it's found with smoky quartz crystals.

That's called a combo. And mineral collectors have been going nuts for this stuff for ages! I totally get it too- It’s freaking beautiful. Jaw droopingly gorgeous! A large amazonite and smoky combo even made the cover of a mineralogy textbook.

That color! Why's it blue-green? Is it real?

Microcline feldspars come in gray, white, salmon, yellow - and of course the amazonite variety is blue-green! Usually, they're naturally colored but it *is* possible to turn white or gray microcline into amazonite in a lab. So buyer beware...

In nature, that blue hue comes from traces of lead and water in the crystal being subject to high-energy radiation. Thanks again to Dr. Rossman at CalTech and his student, Anne Hofmeister for doing the research and sharing your work with the world! Makes sense to find natural smoky quartz and amazonite crystals together, since radiation is a key ingredient in what makes smoky quartz black. You can read more about that here.

Hardness

Microcline's hardness is 6 - 6.5. Quartz can scratch feldspar and feldspar can scratch selenite (and all other types of gypsum) calcite, fluorite, apatite, glass and a steel knife.

Where's it found?

Feldspar is the most common mineral in the Earth's crust. Beach sand includes little feldspar sand grains. Metamorphic rocks contain feldspar. And granites are mostly made up of feldspars. In typical granites, the feldspars are usually small. But in pegmatites (these linear bodies within other rocks that have big crystals and fun minerals) they're usually inter-grown with quartz and the can get pretty huge.

In underground fractures within the main rock bodies (pegmatites), crystals have enough room and time to grow large and well formed crystals like these amazonites from Colorado. More commonly, they grow as masses - not well formed crystal shapes.

Now as far as amazonite occurrence specifically... It's not the most common type of feldspar. But great specimens are most most notably found in Colorado, Virginia, Brazil, the Ural mountains of Russia and Egypt. Interestingly, amazonite's NOT found anywhere along the Amazon river.

Lessons from Amazonite

From "An Indian Prayer"
"Let me learn the lessons you have hidden in every leaf and rock"

The characteristic white lines that give this gorgeous mineral amazing texture and depth, form as compositionally incompatible segments crystallize. They fractionate out but are actually intergrown. And together they make a beautiful whole.

We're multi-faceted beings as well. Perhaps there are parts of you- maybe in your current reality or maybe the dreams in your heart, that seem incompatible.

Let's learn from the amazonite crystal. What if these seemingly different parts of you aren't pulling you apart?

Maybe they actually fit together perfectly. And impart even more beauty on your already rich life. Be at peace and trust that all these parts will come together.

Amazonite's blue-green color brings a soul penetrating, soothing vibe reminiscent of a blue-green sea. So let it remind you to be like water and go with the flow.

Know that you are beautiful. Know that you are whole.

Want your own amazonite crystals?

I've sourced some amazing amazonite crystals for you, from my friend Carl Holzer. They come from the Pike's Peak area of Colorado (Carl also hand digs the smokies on our website)! There are several single, well formed crystals, clusters and combos (remember those are the smoky quartz and amazonite crystals together).

You can shop the amazonite collection here!

References

Anne M. Hofmeister; George R. Rossman, A spectroscopic study of irradiation coloring of amazonite: structurally hydrous, Pb-bearing feldspar in American Mineralogist (1985) 70 (7-8): 794–804.

George Rapp, Archaeomineralogy, Second Edition, 2009; pub. Springer

William D. Nesse, Introduction to Mineralogy, Third Edition, 2017; pub. Oxford University Press