Stone Stories: Yeast cultures in pulverized granite

(August 2011) Granicium is the name of a new composite stone developed in Germany: based on ground granite, the raw material can be formed like ceramics or worked like natural stone e.g. polished. The material was developed by Coburg-based Denk Ceramics. „It is suitable for objects too costly or impossible to produce in granite stone“, according to company CEO Fabian Denk.

The production of Granicium begins by grinding granite to various sized kernels – refuse from quarry production can be used for this, too. Then so-called effective micro organisms (EM) are added in the form of yeast cultures as well as activated water. Unlike in the case of dough, yeast does not make the mass light and fluffy, but lends cohesion.

Cohesion is what allows the pulverized granite to keep its shape. The raw mass is then subjected to high pressure with the help of a hydraulic press imitating the natural formation of rock from lava.

The moulded object is allowed to dry over a period of approx. 2 weeks and is subsequently baked at temperatures of 1,300° C in a kiln again imitating the natural evolution process of granite. This is where the kernels cinder, i.e. where the quartz particles melt at the edges and cake together.

The yeast cultures burn up and ensuing cavities are filled with surrounding material – an important step for resilience and durability as well as resistance to frost.

Considering the complex process of production Granicium is no competitor to granite. „Its niche is where the creativity of ceramics and the special properties of natural granite are sought“, according to Fabian Denk.


Photos: Denk Ceramics