If you read up on the Coobina Chromite deposit, they also mention common opal with nickel impurities giving it the green colouring, so that may be what the first two rocks are. The other two look closer to chrysprase, maybe just not gem quality??
There is a an old CRA uranium prospect on the western side of highway, just south of Newman that has what I presume is Prasiolite. I collected some specimens from there years ago, where the the quartz has changed to a green colour (some half & half). From what I have researched, the naturally occurring ionising radiation in these areas may contribute to the discolouring of the quartz over time.
Yes, I'm thinking opal as well. For both rocks. Though the 2nd one is throwing me a bit. It could very well be a green chalcedony (like chrysoprase is). I would say to do a hardness and s.g. test, but chalcedony and common opal are very close, so not sure if it would help (read: confessing that I would muck them up, most likely. You might be way more accurate).