Excess pf alumina in the clay

The central part of a tree is called

The principal constituent of every kind of brick earth is alumina.

The size of mould for bricks should be

The compressive strength of a good Portland cement and standard sand mortar after 3 days of curing should not be less th…

Which of the following statement is correct?

The colour of granite is

The rocks formed due to alteration of original structure under heat and excessive pressure are called metamorphic rocks.

Excess of silica in the clay