Help Me ID This Rock. Is it safe?

[MDT]

I found a whole bunch of cool looking rocks today in my backyard, but I have no idea if they are safe because I am unable to identify it.

It's metallic grey in colour and each side (3 sides) is different.
The flat side, which I think was split in half, is smooth and dull in colour. The bottom side is reflective and shiny, while the uneven front side sparkles a bit in light.

I live in Vancouver, BC if that helps at all.

I want to know if this rock is safe because they have a very nice look.

 

[Fishinfreak]

Try pouring vinegar on it. If it fizzles, then you don't want to use it because it will most likely cause pH swings.

 

[Gillie]

Looks like a type of marble, if so it will likely alter your water chemistry, but like Fishinfreak said test it with vinegar.

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[Mebbid]

Even if it does bubble it doesn't necessarily mean it's a bad thing. It will slowly increase your pH, although the softer your water the faster it will cause it to uptick. It should max out at just a hair over 8.0.

 

[lovecatfish]

Well. If it is marble, there shouldn't be a problem right? Calcium carbonate is insoluble in water. So... Maybe I'm wrong

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[MDT]

Thank you for all the input guys.
I have tried the vinegar test and nothing happened, but it doesn't mean it could be safe.
The rock looks like it may contain a ton of metals because of the gleam and shine it has.
I can't have any heavy metals leeching into the water

So far, most people I ask are telling me it's a type of schist. I'm going to go visit a geologist on Thursday to get her professional opinion. She is guessing it's gneiss, which actually looks the closest to my rock based on pictures so far. I'll keep you posted.

 

[lovecatfish]

Im not a chemist or what not, by if metals are to leech into your water, they have to be in the form of a salt which is soluble, so I doubt it will leech heavy metals into the water, I may be wrong once again...

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