Code:
$ grep libblkid /var/log/packages/*
/var/log/packages/util-linux-2.21.2-x86_64-6:lib64/libblkid.so.1.1.0
/var/log/packages/util-linux-2.21.2-x86_64-6:usr/man/man3/libblkid.3.gz
/var/log/packages/util-linux-2.21.2-x86_64-6:usr/lib64/libblkid.la
So that would be the util-linux package.