Would the rocks in my area be safe?

[redruckus]

I live on the north shore of lake superior and there are alot of very nice round mamazingly colourd rocks mostly granit and shale but ther are a few other types i havent been able to identify would these rocks be safe for my aquarium or do i have to worry about having and hiden minerals or metals that would some how leech out of the rocks and kill my fish...i would obviously give them a thurogh boil befor it put them in my tank

 

[Conneralbrecht]

Pour some vinager on the rocks, if the vinager bubbles the rocks are unsafe. Also make sure you scrub the rocks off pretty well.

 

[redruckus]

the rocks i would br getting a very sun bleached or from beaches so boiling them for 30min or so would kill anything on the rocks. i am goin to try to pick rocks that dont have anything growing on them.. but the vinager trick hope fully works but i know that works with very dangerous rocks im thinking after a few months what would end up in my water if it has small amounts that dont react but leach overtime

 

[dkpate]

I use slate, granite and shale with no problems. If a rock is crumbly don't use it.

 

[redruckus]

from what iv read im worried about quartz in the rocks because sometimes i can hold trace metals like copper and iron that can be deadly to fish

 

[dkpate]

True. I just found this site, and it's pretty informative! I wish I would have known about it when I was rock hunting....
Know Your Rocks - Sedimentary, Igneous, Metamorphic

 

[redruckus]

http://images.imagestate.com/Watermark/1901189.jpg this is more less the exact same kind of beach i will be gathering rocks from so its very hard to diferentiate what rock is what colour and whats in it.. your more less down to granit is speckled, slate and shale are not and are usualy smoother

 

[dkpate]

All the shale and slate around here is black. I would say you would be safe with anything that doesn't have shiny sparkles, isn't lava rock, isn't crumbly and passes the vinegar test.