What is Siliceous rocks?

Question

what is it ? how is it formed?

Thanks!

Answer 1

a siliceous rock is all most made up of the min earl silicon and it is a igneous rock

Answer 2

Siliceous rocks are any rocks that consist largely or almost entirely of silicon dioxide (SiO2), either as quartz or as chert.

Siliceous rocks are sedimentary rocks.  They form as do all sedimentary rocks do.

Sedimentary rocks are formed in two ways. Some are formed by pressing together or compacting loose particles which have been deposited on land or in water bodies such as seas or lakes. These loose particles are called sediments. Other sedimentary rocks are formed by the crystallisation of dissolved minerals.

The most common siliceous rock is Chert other types include Diatomite. They commonly form from silica-secreting organisms such as radiolarians, diatoms, or some types of sponges.

EDIT:

Siliceous rocks are not igneous rocks; they are sedimentary rocks.  See:

http://ezinearticles.com/?Sedimentary-Ro...