http://wow.allakhazam.com/db/object.html?wobject=168
for rich thorium veins
http://wow.allakhazam.com/db/object.html?wobject=64
for small thorium veins
http://wow.allakhazam.com/db/object.html?wobject=116
for ooze covered thorium veins
http://wow.allakhazam.com/db/object.html?wobject=355
for ooze covered rich thorium veins
Guess thats that, good luck on mining them!