Can all rocks be dated radiometrically?

Question

Can all rocks be dated radiometrically?

Answer 1

Most igneous rocks can be except some of the finer grained extrusive varieties (e.g. pumice, volcanic glass).

Metamorphic rocks can but may not give you the correct age of formation because of subsequent heating events.  You may only get the age of of the most recent metamorphism.

Sedimentary rocks can't be radiometrically dated.  If one were to obtain a suitalble sample for age dating the date would be that of the parent rock that contributed sediment to form the sedimentary rock.

Answer 2

No, only rocks that freeze in the radioactive elements and the decay products into the rock at the time of formation can be dated.  You can't date a rock that has seen one, the other, or both migrating in and out of the rock.  That is why sediments are generally no good to date by radiometric means.  

A rock that has undergone some change, like alteration or metamorphism, can sometimes be dated to give both the time of the change and the original time of formation. This can only be done if the parent and daughter can move between minerals but don't leave the rock.

If the parent or daughter move in or out, you will either think the rock is older or younger than it really is.  the ratios will be messed up.

Answer 3

No.  Only those that contain suitable materials, such as uranium, can be dated.