Azul Imperial

Azul Imperial

Description of colouring and granulometry: fine-grained quartzite whose shading is very similar to blue Macaubas, the only difference in this case being that the shades are softer and lighter, creating a pastel effect. The base colour is a very light blue containing variagted stripes which fade, with a more or less accentuated continuity, from indigo to violet and dark blue. The colour changes, which can also be sudden, give it a delicate and charming appearance. The darker constituents form linear streaks which overall give the material an oriented pattern. The blue colour is mainly produced by the cyanite, a mineral made up of aluminum silicate. The slabs’ design has and undulating trend, with horizontal and oblique planes separated by stripes with very different colours; the curvilinear character of the shapes depends on the cut which is carried out at a right angle, maintaining the marking produced by the original metamorphism process. It is quarried in the Serra Dos Brejinhos and in the Povoado Monte Alegre in Boquita in the state of Bahia.

Other commercial variety: Green Imperial Blue, Imperial Blue, Azzurro Imperiale, Cloudy Imperial Blue, Azul Imperial Verde, Azul Imperial Nublado, Azul Boquira.

Prevailing applications: interior and exterior. Wall cladding, flooring, slab works.

Mineralogical composition: quartz 80%, cyanite 8%, muscovite 8%, secirite 2%, other (zircon, opaque minerals).

Physical and mechanical properties: volumetric weight: 2678 kg/m3; absorption coefficient: 0.12%; apparent porosity: 0.33%; compression breaking load: 116.76 MPa; compression breaking load after gelivity: 212.9 MPa; bending strength: 23.77 MPa; coefficient of thermal expansion: 13.3 (mm/m°C)x10-3; shock resistance: 0.8 m; wear test: 0.19 mm/500 m; Mohs hardness: >5; static deformability modulus: 61.54 GPa.

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Description from
TRE
Collection: materials, manufacturing and uses
ANNUAL STONE
by
Beatrice Zoppas