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I'm Quarzi and I'd like to tell you a bit about myself.

Mineralogists call me deep quartz or α-quartz.

I have been called quartz for around 600 years.
It was invented by miners in 
Saxony, Poland and Bohemia (Czech Republic).
But scientists can no longer really understand what it means.
There are various theories: Dwarf, robbed, cross-cut ore, evil ore or wart.
All these translations show that quartz was not a popular mineral 
because miners preferred to find valuable ores.

I can appear in many different colours.
Each has its own name.

A colourless, transparent quartz is called rock crystal.
If it is white and opaque, it is called milk quartz.

Smoky quartz is grey to dark brown.
Morion, on the other hand, is really black.

Purple quartz is called amethyst,
yellow is citrine and green is prasem.

Not to be forgotten is the pink-coloured rose quartz.

Quartz crystals have a long shaft,
which consists of six sides.
There is a pyramid at the top.

Over the course of time, special growth forms have
given special names.
This works in a similar way to colours.
There are, for example, sceptre, window, thread, 
artichoke, even phantom quartz crystals.

My arms and hands are sceptre quartz, for example.

I consist of the elements
silicon and oxygen (SiO₂).

After the group of feldspars
I am the most common mineral in the earth's crust.
So you can find me all over the world.

I am a component of many rocks, such as
granite, rhyolite, gneiss, sandstone or quartzite.

Beautiful crystals grow in fissures,
such as rock crystal. Fissures are crevices,
that break open during rock formation.
Hydrothermal veins are formed from
hot, aqueous solutions that rise from the depths
the earth's surface. They cool down in the process
and crystallise out.
You will often find me there with the minerals
Fluorite (fluorspar), calcite (calcspar), barite (heavy spar),
galena (lead glance), sphalerite (zinc blende)
or pyrite (fool's gold).

I'm harder than your fingernail.
So you can't scratch me.

I'm about as hard as glass.
You can just about scratch it with a quartz.

If you want to know more about the Mohs scale of hardness,
then have a look at the profile of fluorite.

I have no cleavage, but show a great fracture.

If you hit a piece of quartz with a hammer,
curved fragments with ring-shaped lines are formed.
The fracture surface looks like the imprint of a shell, 
which is why it is called a conchoidal fracture.

Without my silicon, there would be no computer chips or solar cells. 
I am virtually indispensable for the electronics industry.

I am a raw material for the production of glass and ceramics.

Microscopes and telescopes have lenses made of quartz.
Glass lenses and window panes filter ultraviolet light.

Quartz can also be cultivated. 
It is used, for example, as oscillating quartz in quartz watches.

And, of course, jewellery has been made
from me for many thousands of years.
I can even often be found in royal crowns.

For at home, here is another craft sheet with me.

You can colour me in all the colours you like.
But make sure you know what name I have to be given!