[meteorite-list] ureilites and earth

[Abdelfattah Gharrad]

Dear list members,

I really thought that ureilites are a good example to help learn more about the age of the planet earth? is this right please?
the carbon crystallized on ureilites can give an idea of the age for the long time of its crystallization.
But, there is a difference of ureilites (kind of ureilites like eucrites ... etc). So what kind of ureilites that have ancient characters?

Thanks,
Abdelfattah.