Quartz

In my Amethyst Blog, we learned that quartz (SiO2) makes up over 10% of the Earth’s crust and is the most abundant mineral on earth. However, the only colour of the rainbow we touched on was purple (amethyst).

There are more varieties of quartz than any other mineral. The different types of quartz are characterized by a specific trace element (like iron in amethyst) or inclusion.

Let’s explore some of the kaleidoscope of quartz!

Clear Quartz

Colorless and transparent

No inclusions or trace elements

Smoky Quartz

Light brown to almost black

Formed when clear quartz is naturally radiated by surrounding rocks.

Additional radiation will darken the crystal

Milky Quartz

White to greyish white

Formed when tiny bubbles get trapped in the crystal structure during formation

Rose Quartz

Light pink

Formed when titanium is trapped in the crystal structure

Citrine

Yellow to brown

Formed when hydrous iron oxide is trapped in the crystal structure.

Amethyst

Purple

Formed when iron is trapped in the crystal structure

Hawk’s Eye (Blue Tiger’s Eye)

Grey to blue

Formed in tiny cracks when fibrous quartz and blue crocidolite grew together.

Chalcedony

Microcrystalline Quartz - Various Colours

Forms when silica-rich water percolates through fractures and voids depositing microscopic quartz particles. This forms microcrystalline layers that can vary in colour due to microscopic or macroscopic inclusions.

Includes carnelian (reddish orange to blood red), Onyx (black & white), Bloodstone (green & red), jasper (various), agate (various)

Tiger’s Eye

Gold to brown

Hawk’s Eye that has been weathered causing the iron in crocidolite to oxidize to the gold to brown.

Aventurine

Sparkling green, brown, reddish brown, peach, yellow & white

Inclusions of shimmery minerals. Colour is dependent on the type of mineral inclusion.

Green - green mica (fuchsite)

Brown - pyrite

reddish-brown - hematite

Blue - dumortierite or crocidolite

Bloodstone

Carnelian

Agate

This colourful bunch covers some of the more commonly seen few types of quartz. Let me know if you would like me to expand on any of the mineral discussed in this post.

For my next post, I’m going to explore some turquoise minerals. You’ll want to hear about these minerals and their imposters!