Anyone have an idea what this mineral is likely to be? In the water it has a more grey silvery sheen and stands out a bit from the usual black heavies it travels with.
It can be lifted with a magnet and comes from the Shotover.
Calling on the @Lammerlaw brain trust… you might have a good idea?
Hi Gavin. You aren’t overlooking the obvious are you, Iron stone? As you will Know, The Shotover is full of it & has way more than its fair share of it. Pain in the butt actually. 
JW 
So the black stuff is magnetite and this is probably iron stone. Cheers.
I’ve probably seen it before, but it was really popping out at me last trip in.
Of the standard metal groups i think only iron,cobalt and nickel are magnetic. That narrows your options Gav
Cheers Darryl, much appreciated. That certainly narrows it down a bit. Cobalt and nickel certainly look like they could be contenders. I’ll do a bit of research and see if the Shotover is known for anything in particular.
As JW said, its almost certainly iron given the local geology though.
Hi Gavin. The Shotover is most certainly known for its abundance of iron sands as you will know when you look at what your riffles are filling up with. Mind you, you can just see it all over the place. The sands of course are derived from the the iron stones, rocks & boulders. Same with the Arrow & the Cardrona.
If you were down this way you should have made contact. Even Mal paid me a visit. 
JW
@kiwijw LOL, I’m very aware of the abundance… I’ve nearly sunk my dredge due to the build-up of these iron sands in the riffles. Popped up from water and found my dredge almost vertical as a result 
And apparently my mate had the same issue this year. The 4" Keene dredges seem to struggle with all the black sands… need to work out some sort of hydraulic riffle setup.
Most of the heavies I notice are very black in colour, these stood out from the crowd as they stood out in the mix underwater as they looked a lot more silvery sheeny. Hence the curiosity piqued.
Loads of the iron stone in the shotover and arrow. Had the same happen to my dredge a couple times. The concentrates cleanup I could barely lift at the end of a solo day on dredge. If you go down the track under the skippers bridge there are a massive boulder of iron up the bedrock bank a few years ago. Guess it’s still there, just a short walk up from the shed and before the bridge. Probably hauled out of the way by l and m when they went through there in the 80s.
Looks like it could be platinum if weak magnetic pull cobalt or nickel in with it at 10% ratio gives it magnet pull obv the more nickel or cobalt more magnetic it is,
I recall Lammerlaw telling in one of his recounts of dredging up heavy black stones and not knowing what they may have been, throwing them back into the creek. A few years after reading that post I read of heavy blackened pebbles (found out later to be gold stained by a discovered cinnabar lode upstream) being plucked from the sluices by the old timers and thrown into the tailings.
Definitely not in your case as they wouldn’t be magnetic but always worth checking!
