ANGOLA BLACK

How much variation should be expected in granite?

Granite is a rock that has been formed deep under the Earth’s surface over millions of years as molten magma slowly flows, cools, and solidifies underground. It is composed of different minerals, including quartz, feldspar and mica and its color is a response to the mineral content of the stone. This is why variation in grain structure, veining, color, and other visual characteristics are normal in all granite varieties and should be expected.

Where can we see the stones and finishes?

We provide samples to our design and trade customers to facilitate granite selection and specifications. One of our team members will gladly assist with any requests. Our granite samples are intended to represent the basic color tone, texture, and markings of the granite as closely as possible in a small size. The samples may not represent the full range of variation of natural stone, and natural markings and background variations are to be expected in full size architectural work.

Can different finishes change the appearance of the same granite?

Yes. The selected finish influences both the appearance and functionality of a granite. A polished finish deepens the color of stone, increases reflectivity, and highlights mineral patterns. A honed finish produces a surface that is smooth and with low or no reflection. Thermal, bush-hammered, split-face, and rock-pitched finishes generally appear lighter in color and emphasize texture and shadow. All textured finishes provide slip resistance, making them a common choice for exterior paving and hardscape applications. Combining multiple finishes within the same project helps add texture, interest, and visual balance.

What is ASTM product data for granite?

ASTM test reports quantify key physical properties of a granite, including density, absorption, compressive strength, modulus of rupture, and flexural strength. These values provide a common basis for comparing materials and evaluating their suitability for paving, cladding, coping, stairs, curbs, and other dimension stone applications. While ASTM data is an important part of the specification process, successful stone selection also considers factors such as finish, panel size, anchorage design, environmental exposure, and the intended use of the stone. Blackhill provides ASTM test data for all granite varieties we offer.