What is Schorl? Exploring the Black Tourmaline

Have you ever seen a beautiful, jet-black crystal with a mysterious shimmer? It could very well have been schorl, the most common variety of the mineral group known as tourmaline. Tourmalines are fascinating because they can come in a dazzling rainbow of colors, but schorl, with its deep, inky blackness, has a charm all its own. In this article, we'll dive into what makes schorl unique, where the name comes from, its properties, and how it has been used throughout history.

What is Schorl? The Shiny Black Mineral

Picture a jet-black crystal, maybe long and pointed like a witch's hat. This is schorl, a fascinating mineral that's much more than just a pretty (or spooky) rock.

Schorl belongs to a group of minerals called tourmalines. Think of the tourmalines as a big, colorful family – there are pink ones, blue ones, even watermelon-colored ones that are pink and green! Schorl is the most common member of this family, and it's always some shade of black.

What's in a Name: The Word "Schorl"

The word "schorl" likely has roots in the ancient mining towns of Saxony, Germany. It's believed to be derived from an old German word  (either "schörl" or "schurel") which was used by miners to describe worthless or troublesome minerals. Over time, the term "schorl" became specifically associated with black tourmaline. 

Science Stuff: What Schorl is Made Of

Let's get a bit more scientific.  Schorl is a complex mineral with a fancy chemical formula: NaFe3+3Al6(BO3)3Si6O18(OH)4.  Let's break that down:

• Sodium (Na): This is a common metal, just like the kind found in table salt.

• Iron (Fe): The stuff that makes strong tools and turns red when it rusts. This iron is what gives schorl its dark color.

• Aluminum (aluminium) (Al): Used to make everything from soda cans to airplanes.

• Boron (B): An element used in cleaning products and even rocket fuel.

• Silicon (Si) & Oxygen (O): The building blocks of most rocks and sand.

• Hydroxide (OH): A combination of oxygen and hydrogen, kind of like a tiny bit of water stuck inside the crystal.

All these elements come together in a special way to create those long, shiny schorl crystals.

Where Can You Find Schorl?

Schorl is a tough cookie and can form in lots of different places:

• Igneous rocks: These rocks form when hot, molten liquid (magma or lava) cools and hardens. Granite is a type of igneous rock, and you can often find schorl crystals nestled inside it.

• Metamorphic rocks: These change from one kind of rock into another through lots of heat and pressure. Think of this like a lump of dough being squished and baked, changing how it looks and feels. Schorl forms in rocks like gneiss and schist.

• Pegmatites: These are special types of igneous rock that have super-large crystals. Sometimes you can find giant schorl crystals in pegmatites!

Schorl is found all over the world – places like Brazil, the United States, across Europe, and even in Africa.

What's Special About Schorl?

Besides being a cool-looking mineral, schorl has a few quirks that make it interesting:

• Piezoelectricity: This is a big word, but it basically means schorl can generate electricity when you squeeze it!

• Pyroelectricity: This means schorl can also generate electricity when you heat it up!

These properties aren't strong enough to replace batteries, but they are used in some scientific instruments.

A Bit of History

Humans have known about schorl for centuries, but its name has changed a lot over time. The ancient Greeks had a word, "lyngurium," which probably referred to some types of tourmaline, including schorl.  But it wasn't until the 1500s that the name 'schorl' became common.  At this time, schorl wasn't thought to be a very valuable mineral by itself, as the name might suggest!

Schorl Today (2023)

Although schorl isn't as flashy as its gem-like cousins in the tourmaline family, it still has its uses:

• Specimen for collectors: Mineral collectors love the long, shiny black crystals.

• Scientific purposes: Schorl's electrical properties make it useful in some scientific tools.

• Small-scale jewelry: Some people do create jewelry from polished schorl pieces.

Let's Wrap It Up

Schorl is a fascinating part of the natural world. It might look simple, but there's a lot going on—from its complex chemistry to its unique properties and history. Next time you see a shiny black crystal, it might just be schorl!