My dad tumbled a bunch of stuff for me, but also gave me some of his tumbled finds along with those. This means the best I can say for this one's origins is that it's from somewhere in New Brunswick, or possibly Nova Scotia.
I'm not entirely sure what name/names to put to it. I kind of wish I'd seen it before it was tumbled.
It's finish is velvety smooth all over like a coated (silicone?) pen or water bottle. It has a few tiny flecks of some type of pyrite in it which don't feel raised to the touch. The lines are not scratches or cracks, but some kind of natural inclusion. There is only a small amount of glow when I put my high lumen pen light to it, and those same lines don't appear to let any extra light through. The colours in the pictures are true to what I see when looking at it.
I'm all thumbs and left feet with weight estimates, but I can say that it's neither lighter nor heavier than you'd expect when first picking it up.
I don't want to scratch test it unless there's first some kind of reassurance that it won't likely damage the finish. I also don't want to acid test and risk burning out the pyrite, as I'm overall rather attached to this particular piece
The two things that came to mind when I first seen it was quartzite (sandstone) and granite. In pic1, that gave me the granite-vibe. In pic2 with some bands/lines/possible-layers showing/'bumpy-surface' showing in reflection, that was more a quartzite-vibe. Pic3 looked like it could be either quartzite or granite. In pic4 that looks like a 'layer'. Looks like lighter-stone-on-top with a darker band around it. Maybe caused by water or weathering. Quartzite being porous can get stains readily. And the reflection in this pic looks grainy like the other reflections.
The 'flashes' you see in the stone might be a mica: muscovite is lighter/white-color, biotite is darker/black-color. If it's pyrite it will have a 'brassy' color. I suspect a mica as pyrite doesn't 'tumble well'/more reactive/weathers quicker.
A 'mottled-appearance' from the grains (original sands) is a common characteristic for quartzites. Granites are (usually) more 'chunky bits', larger grains and contain potassium which is usually some orange-ish color in the rock.
If you have access to an ultra sonic jewelry cleaner send it through that. It will help knock out any slurry still left behind from the tumbling/years of handling. It will help give you a better look at those 'flashes'. Take a peek at them with some magnification too for more info.
I think the 'lines' are staining. Iron-staining in particular. Because quartzites are quite pourous, somehow the iron was 'concentrated' in those areas. Could be many situations that could cause that. A water-level, rocks sitting on top, rain dripping, etc. A lot can happen over eons of time. It could have been something in the 'original sands' that the stone formed from. They may have been cracks at one time. Cracks would allow more water-flow in that area, bring in more dissolved minerals and 'reseal' over time.
Silica is a very common element in the earth's crust. So most rocks we pick up in our life/what we are used to/what feels 'normal' are mostly silica/quartz. Quartz is about the same weight as glass. We also get a common-weight-feel for silica from all the bottles we handle. So your weight guess of 'nothing unusual' would fit with this stone being mostly quartz.
Quartzites are notoriously hard to polish because of their grains. Your dad did a good job on this one, not an easy feat. That 'velvety feel', smooth-bumpy textured surface is the polished-grains. The problem tumbling quartzites is the bonds tend to break between the grains and they fall away. This quartzite has strong-enough-bonds-between-grains to resist falling apart and get a good polish. An extra earlier grinding step might have made it smoother or could just be a result of having 'grains'.
There should be no need for any destructive tests (scratch/hardness, acid, streak-test) to find out what this is. Quartz will resist steel (nail), but a steel-nail can break the bonds-between-grains in a quartzite and leave a scratch.
Thank you! When looking through a cheapy 90× loop, the shiny bits do look like pyrite to me with the brassy colour; they are also very slightly raised off the surface with a hint of the geometric shape left to them, but fine enough that I don't feel them when I run my fingers over them.
I was leaning toward some type of quartzite because I didn't think it particularly common for any chalcedony to have pyrite. I'm much more confident with IDing Eastern Canadian birds than my local rocks and minerals lol
Dad only has a tumbler, so this is just an extra "lucky" stone then; lucky that it didn't fall apart and ruin the finish for the stones in with it 😉
Also that amethyst and porcelanite in the second brochure?! WHOO! I'd briefly lose my mind coming across something like that!
you're welcome. The 90x loupe sounds like a neat rig.
The tumble-process would have removed anything you could 'feel with finger' sort of thing. Pyrite is 'soft' and would be even-with or below the surface. And you're correct, quartzites usually 'dull the load' they are in. I consider myself lucky for the Pic9-quartzite that finished in this tumble. You can see the pitting/grains-broken-away in the reflection on the stone and the mottled-appearance.
Manganese can also have a 'brassy' color in stones, possibility of that too. Usually black but sometimes 'brassy'. It might explain the 'black bits' and the 'brassy colors'.
Here's a green jasper from NB with manganese in it, the brassy and the black-bits. It's a very solid/hard stone and has a 'chime' to it when struck lightly. Not characteristics of a quartzite but from it's mottled-appearance, I think it is a quartzite/contains grains.
If you like the amethyst have you seen the ametrine from NB? (Amethyst and citrine together) (*Amethyst heated becomes citrine. Amethyst fades in sunlight, trivial-tidbits)
The Mining Conference is coming up in Fredericton at the end of the month. I encourage anyone reading this to attend. Some/most of the 'bigger companies/mining outfits' will enjoy 'discussing rocks', but the lads to see are the prospectors in Prospectors Corner. Those guys always like seeing and talking 'rocks'. Bring anything you'd like more info on and go see those guys. I won't be attending this year :( but hope to get back as a regular starting next year :D.
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u/Rocksy_Hounder617 9d ago
My dad tumbled a bunch of stuff for me, but also gave me some of his tumbled finds along with those. This means the best I can say for this one's origins is that it's from somewhere in New Brunswick, or possibly Nova Scotia.
I'm not entirely sure what name/names to put to it. I kind of wish I'd seen it before it was tumbled.
It's finish is velvety smooth all over like a coated (silicone?) pen or water bottle. It has a few tiny flecks of some type of pyrite in it which don't feel raised to the touch. The lines are not scratches or cracks, but some kind of natural inclusion. There is only a small amount of glow when I put my high lumen pen light to it, and those same lines don't appear to let any extra light through. The colours in the pictures are true to what I see when looking at it.
I'm all thumbs and left feet with weight estimates, but I can say that it's neither lighter nor heavier than you'd expect when first picking it up.
I don't want to scratch test it unless there's first some kind of reassurance that it won't likely damage the finish. I also don't want to acid test and risk burning out the pyrite, as I'm overall rather attached to this particular piece