When we think of granite, we usually think of black or white slabs as they are the most common colours. But can you believe that granite is available in a wide variety of other unusual colours like pink, blue and green? In this guide, Decor Luxury Stones, the leading granite suppliers in India explains all about granite colours and the reasons for the colour variations in natural granite.
Granite: A Quick Overview
From building ancient monuments to beautiful sculptures, granite is one of the most popular natural stones that has been used for centuries. It is a type of igneous rock and contains large mineral grains that are easily visible to the naked eye.
It is a special type of igneous rock known as intrusive igneous. An intrusive rock is a molten rock that was cooled deep inside the earth’s crust and was never expelled above the surface. The gradual cooling creates the visible specks of minerals that we see on granite’s surface. The size of the individual specks depends on how fast or how slowly the rock was cooled.
What creates the colour variations in granite?
Granite is a mixture of various minerals and rocks like potassium feldspar, quartz, mica, amphiboles and other trace minerals. Generally, the typical composition of granite is:
20% - 60% quartz
10% - 65% feldspar
5% - 15% micas
The changes in this composition determine the colour of granite. For example, if the molten rock had higher proportions of feldspar, then the final granite slab takes on a salmon pink hue. On the other hand, if the molten rock was abundant in quartz and amphibole, then the final slab is either black or white with speckled minerals.
Here’s a quick chart that helps you identify the composition of the majority mineral in a granite slab depending on its colour:
||Colour of the Granite Slab
||Yellow or metallic gold
||Dark brown or black
||Dark green or black
Now, let’s break down the different types of granite slabs based on their colours:
It contains mostly quartz (milky white) or feldspar (opaque white).
The small specks of black are due to the presence of small amphibole grains.
If you see a countertop that is 100% white, then you can be sure that it isn’t natural granite. It’s most likely to be a man-made material like quartz.
It's the most popular colour for kitchen countertops as the dark black colour can camouflage stains and spills.
A granite slab must contain at least 20% quartz to be classified as granite.
The pink hue is due to the abundance of potassium feldspar.
The base of the slab is pink and it is dotted with specks of transparent/semi-transparent milky-white quartz or dark brown/black amphibole.
Black and White Granite
It contains equal parts feldspar, quartz and amphibole giving it a speckled black and white look.
It's another popular colour that is used for kitchen and bathroom countertops.
This granite takes on a darker colour than salmon pink granite.
The red colour is due to the presence of iron oxide (hematite) grains within the feldspar.
Technically, blue granite is not actual granite. It’s a type of rock known as Larvikite, that belongs to the igneous family of rocks. It's a variety of monzonite. It's commonly known as blue granite.
Another alternative is Anorthosite that is also sold as blue granite.
Again, technically there are no green granites but other stones like green marble or green soapstone are sold off as green granite, since they have similar properties to granite.
Amazonite is a rare variety of green granite that contains feldspar.
Hope this guide clears up all your queries about granite colours. Bookmark this page and refer to it when purchasing granite slabs for your property. Get in touch with Decor Luxury Stone, the leading granite supplier in India to source high-quality, premium granite slabs at the best prices.