While browsing the wide selection of Granite and other Natural Stones at The Granite Place, you’ll notice a rainbow of colors and patterns in each individual slab. Every speck, streak, color, and crystal you see in Granite is a different kind of mineral, each with their own visual and physical properties. Whether you’re shopping for a new Granite countertop, or curious to learn more about your existing Natural Stone Surface, this guide will help you identify some of the most common minerals you’ll come across.
About Minerals
Minerals are the basic ingredients of Granite. In fact, all Natural Stone is composed of minerals in different varieties, ranging from large crystal deposits to fine grains only visible through a magnifying glass. Granite mostly consists of the minerals Feldspar and Quartz, along with Amphibole, Mica, Garnet, and others.
Let’s take a look at some of the minerals you’ll come across in our Natural Stone Showroom!
- Feldspar
Feldspar isn’t just the main ingredient of Granite, it also happens to be the main ingredient of the Earth’s crust. It’s the most abundant mineral on Earth, and often serves as the background or base color in Granite countertops.
Feldspar is a hard and durable material, typically measuring around 6 on the Mohs Hardness Scale. It won’t etch, scratch or stain under most kinds of use.
It can range widely from any shade of black, to white, to nearly every color in between, meaning color may not be your best clue in identifying Feldspar.
You can usually identify Feldspar in Granite by its shape and texture, as it often appears in blocky “chunks.” These chunks can vary in size from small to enormous, and will often feature a subtle striped or grooved pattern when looked at closely. In Granite’s magma form, pieces of Feldspar often don’t liquify, and retain their shape and structure, floating in the molten mix like ice cubes in a Bloody Mary.
- Quartz
Not to be confused with the man-made stone surfaces by the same name, Quartz is the second most abundant mineral on Earth. Quartz is very popular outside the world of countertops for its durable nature and its ability to retain and conduct energy. It’s used in many household items and electronics, from wristwatches to bomb disposal equipment.
Quartz is even harder than Feldspar, with a Mohs hardness of 7, and is incredibly durable and long-lasting.
Commonly clear or translucent, Quartz will have some remarkable color variety in different Natural Stones, sometimes influenced by the neighboring minerals surrounding it. Quartz can have colors like black, gray, pink, white, and even purple.
Quartz can be any kind of shape, as it mostly occupies the gaps between other minerals while it cools from its magma form. It is the last mineral to cool and harden from a molten state, so any cracks or holes left by the solid Feldspar are quickly filled in by Quartz. In most Granite slabs, you can easily identify Quartz from its signature crystallized appearance.
This slab of Crystal River Granite has a large Quartz deposit running through the Feldspar, accented by Amphibole crystals and thin lines of Mica.
- Amphibole
Amphibole is also known as Hornblende. Often quite easy to identify because of its contrast with the surrounding Quartz or Feldspar, Amphibole is sometimes visible in lighter Granites in striped or scattered hash-mark patterns.
Amphibole is about as hard as Feldspar at a Mohs hardness of 5-6. It has similar properties to glass.
Amphibole is solid black in color, usually in thin, elongated crystals. The crystals are usually rectangular or nail-shaped, but can sometimes appear in smaller, clustered pieces.
White Galaxy Granite has great examples of Amphibole crystals, as they are a stark contrast to the white Feldspar and Quartz background.
- Mica
Mica can sometimes be confused for Feldspar, due to its similar appearance. It’s very common to find Mica in a slab of Granite, usually creating a textured or pattern within the stone.
You won’t normally find large deposits of Mica anywhere in residential-grade Granite, as it is a very soft and pliable mineral. It’s commonly found embedded within the Feldspar, appearing as dark, narrow lines on a polished Granite surface.
Mica can be black, metallic, or silver in color. It’s found in both dark and light Granites, and is the source of that popular, reflective “glittery” pattern found in many Natural Stone countertops.
Mica is typically present in the form of thin, wavy flakes or glinting, metallic deposits. When in doubt, Mica’s appearance is easiest to identify on the unfinished edges of a granite slab, where you can see the paper-thin flakes a little more clearly.
Blue Dunes Granite has a more finely mixed set of minerals, as geological stress and pressure has constantly stretched and compacted them over millions of years. An educated eye can still identify the different minerals in this sample.
- Garnet
A mineral you may recognize from your grandmother’s jewelry, Garnet is more common than you might think. Although it is considered a precious stone, it is present in several popular Granites, and can provide a fun splash of color to your countertop.
A particularly hard and durable mineral, Garnet measures around Mohs hardness 7.
Garnet is obviously quite easy to identify by its color, since it only ranges from bright red to dark red. Garnet can appear in cloud-like clusters, tiny circular deposits, or in scattered flecks.
This slab of River White Granite has plenty of garnet deposits throughout its white Feldspar base. Notice how pressure and geological movement have stretched the Quartz and Mica deposits into long, wavy lines.
While no two blocks of Granite are the same, knowing just these five minerals will make it easier to narrow down the look, color, and style you’re going for in a countertop. Whether it’s to help your shopping experience or to impress your friends, we hope this guide has helped you!
Come and visit one of our showrooms to view our amazing selection of Granite, as well as premium Marble, Quartzite, and Radianz Quartz Surfaces!
Take a look at some “Designer Look” Granite ideas here!
