Strange Speckled Rocks in the Golden Triangle

[TomStatic97]

Hello all! I started back in late April and have been wandering around the Golden Triangle area in Vic, and my recent adventures have taken me to the Daylesford area. So far it's only been around here that I've found it, but when panning, I constantly have been finding stones of various sizes and hardness that are speckled with something shiny inside, as if it's incredibly fine glitter. I don't expect this to be gold, doesn't quite seem like it. If it is gold, it is *incredibly* fine considering the size of whatever is reflecting the light.

Pyrite? Something else? Any clue? Can attach photos/videos if needed

 

[axtyr]

You will need to upload a photo unless you get someone who regularly pans around Daylesford. It sounds like opal from the description of the sparkling. LOL.

 

[grubstake]

"Speckled rocks" sounds like granite to me, in which case the shiny stuff would be mica (but I am not a geologist).

 

[Jaros]

PICS? PICS?

 

[Hawkear]

Withough pics all of us would be guessing and could be a wide range of possible rock types.
Another few suggestions are pyritic slate, a fine sandstone or even basalt which has a fine crystalline structure. All of those would be possible geologically in the Daylesford area.
Really need the Pics.

 

[TomStatic97]

Apologies everyone, I wrote this last night, was going to grab some pics and vids in the morning - better late than never! I've taken some video of two examples I brought home, one smaller piece and another larger piece. Both seem to have the same shine to them, so I'd assume that they're the same material making the shine. The larger piece seems to have some form of iron running through them as well- pretty cool!

 

[grubstake]

Those look like quartzite to me.

 

[TomStatic97]

Those look like quartzite to me.

Interesting, thanks!
Obviously I didn't expect it to be worth cold hard cash, but good to potentially ID what I've commonly found!

 

[Hawkear]

Daylesford geology maps indicate that the bedrock of the area apart from cappings of basalt is made up of quartzites, sandstones and slates. All can have a speckly or glittery type appearance, so a bit hard to tell even from a photo whether the glittery bits are micro quartzy crystals as in quartzite or sandstone or micro mica flakes or pyritic crystals as in some slates.
Suggest get a good loupe and examine it closely to check whether they are crystals or flakes. Even try to prise one off with a needle might be telling as to what they are.
My two bob would be on slate with micro mica flakes.

 

[TomStatic97]

Daylesford geology maps indicate that the bedrock of the area apart from cappings of basalt is made up of quartzites, sandstones and slates. All can have a speckly or glittery type appearance, so a bit hard to tell even from a photo whether the glittery bits are micro quartzy crystals as in quartzite or sandstone or micro mica flakes or pyritic crystals as in some slates.
Suggest get a good loupe and examine it closely to check whether they are crystals or flakes. Even try to prise one off with a needle might be telling as to what they are.
My two bob would be on slate with micro mica flakes.

I reckon that's a pretty good guess! I'll see if I can find something to inspect it closer and check that, thanks!

 

[user 23515]

Stills would be good next time.
Too hard to see detail in the small bit and would like to see larger in still pics from each side.
That said. Metamorphosed sedimentary rock. Looks like there is mica and is lined up on roughly the same plane (foliation from pressure on the original), would love to see it bashed with a hammer and see how it breaks and surface detail, how minerals line up. A metamorphosed Mudstone? Shouldn't really be that much mica in a quartzite as the original sandstone it formed from would have had to have quite a bit of clay (changed by heat into mica).
TBH guessing with out being able to see a clearly photographed freshly broken surface close up and whole specimen.
After all that, I will go with low grade schist.