"Blue Granite" (Image source: MS International)

The color of granite ranges from white to black to pink, but what makes a single rock type so varied? Here, we will discover what makes each piece of granite show a different color, which tells us its mineralogy and origin. You may be an amateur geologist, just curious, or looking for a new granite countertop. For whatever reason, you will be surprised by the huge variety of different granites.

Granite is one of the most widely known types of rocks and is used for everything from buildings to sculptures. It has been used for thousands of years and is regarded as a symbol of status, strength and durability.

Granite is an intrusive igneous rock with large particles (minerals) that are easy to see with the naked eye. The most common granite colors are pink, white, gray, and black variations. However, it is important to note that some of the stones sold as black "granite" are actually gabbro, because granite must contain at least 20% quartz in the rock to make it granite.

Now, let's break down what exactly intrusive igneous rocks are:

Granite is a conglomerate of minerals and rocks, mainly quartz, potash feldspar, mica, hornblende and other trace minerals. Granite usually contains 20-60% quartz, 10-65% feldspar and 5-15% mica (biotite or muscovite). The minerals that make up granite give it the unique color we see in different types of granite.

The relative proportion of different colored minerals in granite is mainly due to the cooling of the original source of molten rock to form granite. If the lava is rich in potassium feldspar, the granite is more likely to appear salmon pink. On the other hand, if the lava is rich in quartz and minerals that make up amphibole, you may see the common black and white speckled granite on the countertop.

The combination of the aforementioned minerals constitutes most of the colors we usually see in granite. Now, let’s break down the distance types of granite and quickly outline what gives them color

White granite (picture source: geology.com)

White granite is a kind of granite mainly composed of quartz (milky white) and feldspar (opaque white) minerals. The small black spots in the granite above are probably small amphibole particles. This may be due to the lack of the chemical composition required to form amphibole, or the cooling process is not suitable for forming amphibole.

If you see a 100% white rock, it is not granite, but more likely an artificial rock that looks like granite or quartz (quartzite) countertops.

Black "granite" (Image source: Granix.com)

"Black granite" is common in commercial rocks, but it is not granite at all. As mentioned above, granite must contain at least 20% quartz, which means that completely black rock is not granite. The most common is that the black granite is actually gabbro, a mafic intrusive igneous rock similar to basalt. Gabbro is mainly composed of the mineral pyroxene, plagioclase and a small amount of olivine (dark green) and hornblende.

Pink granite is the result of the rich potassium feldspar in granite. You can see tiny milky white translucent quartz, dark brown/black amphibole and opaque white feldspar. However, in granite like the above, the main mineral is potash feldspar.

Black and white granite (Source: Wikipedia)

The granite above seems to contain equal amounts of quartz, feldspar and hornblende, forming speckled black and white granite. This is one of the most common types of granite and the one most commonly used for granite countertops.

Red granite (picture source: eurosian.com)

Red granite is a variant of pink granite rich in potash feldspar, in which potash feldspar shows a redder color than pink. In addition, you can get the red color from the iron oxide in the hematite particles or the inclusions in the feldspar, which is basically the same process that makes the rusty metallic ruby ​​red.

Blue granite (photo source: MS International)

You may find ads for blue granite countertops, but this is almost certainly not granite. One possibility is that the rock is actually Larvikite, a type of igneous monzonite, sometimes called "blue granite", even though it is not granite. Another common alternative is plagioclase, which is a rock that contains a lot of blue labradorite, sometimes sold in the form of blue granite.

Green Granite (Source: Kitchen Design Concept)

When advertised as green granite, the stone is usually actually a green marble, which appears green because it contains serpentine. It may also be a green variant of soapstone, incorrectly labeled as granite. The green minerals in granite are not rich, but there are many different rock types that are rich in green minerals. A very unusual way to obtain green coloration is to include Tianhe stone, a green feldspar.

Finally, we will introduce some of the most common types of granite and what gives them inherited colors.

This is the end of this granite color guide. I hope to teach you a lot about different types of granite, from white granite to "black granite". Leave your favorite comment below.