We use a couple different fossicking terms, though these are fairly generalised across the opal fields around Aus.
Specking is what it is just simply fossicking by eye, but Noodling is the term used when you take two bits of timber board and gently crush the opal dirt looking for opal nobbies (which will generally not crush down under the light pressure used to powderise the dried opal clays). This came from the early days all prior to wet/dry rumblers and modern day agitator wash plants coming to the opal fields in the late 60's. The opal level was dumped on the surface and left to dry out to then be noodled through.
Hope that sheds a little light on the topic :Y:
Cheers,
Shauno.