Skip to main content

Posts

Showing posts from August, 2016

UNDERSTANDING NON GLAZED versus GLAZED CERAMICS

Post 143 by Gautam Shah
.
Clays are fine albuminous products formed by decomposition of igneous rocks. Clays are tenacious and plastic when wet. Clays are highly cohesive, have high capillaries and no internal friction. Clays are smooth to touch, sticky and plastic. Clays can also be classified according to their plasticity, or silt content. Hard clays or stiff clays have low sand content, and are difficult to excavate. Fine clays have medium sand content, and can be excavated with slight effort. Soft clays have coarse texture and are easy to excavate. Pure clays are mostly useless because of the high plasticity and excessive shrinkage on drying. Clays, if very plastic, are called fat clays, whereas less plastic clays are called lean clays.
Top layer or organic soils have substantial amounts of organic matters, from the decomposition of vegetation and human, animals excrete. The presence of organic matters makes a soil light in weight and dark in colour. Organic soils usually show high…