# Rose quartz



## Shara (Jan 31, 2009)

I have a piece of rose quartz that I'm thinking about adding to my fish tank. I just poured boiling water over it and it's making little cracking sounds. I'm assuming that's bad sign? What other tests should I do? Or is it just plain, old not safe?


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## zof (Apr 23, 2010)

cold rock plus hot water = rapid temperature change, if you were going to boil it you should have brought the rocks temp up with the water, I'm not sure even if I would want to boil any type of quartz. As for the safe part I will leave that to someone with more experience.


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## Shara (Jan 31, 2009)

I wasn't boiling it. I poured boiling water on it to sterilize the surface. I do that with all my rocks. I'm not sure how others do it. There is a difference between boiling a rock and pouring water that has boiled on it though.


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## Austin (Feb 1, 2010)

Don't think the crackling is a bad sign or anything - not good either though. Doesn't have anything to do with whether it is safe in an aquarium I'm pretty sure. Try the vinegar or HCL acid test and see if it bubbles. If it bubbles, things inside the rock are reacting and it is not safe. I have a feeling quartz is inert but I'm not totally sure. =S sorry.


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## Byron (Mar 7, 2009)

Quartz is safe, provided there is nothing toxic within it that might leech out. "Rust" on the surface could be iron for instance. There was a photo of this in another thread just last week.

Most "regular" type aquarium gravel is made from quartz and it is inert.

I would recommend just scrubbing the rock with a good heavy-duty brush under the hot water tap. This is hot enough to clean the surface, but not sufficient to crack the rock.

The "acid" test won't be necessary if it is true quartz, but if you're not sure, you could put a few drops of a strong acid and if it fizzes the rock is calcareous (and obviously not quartz). A good acid to use is the regent #1 of a nitrate test kit which contains acid. Common vinegar is often suggested, but it is not really a strong enough acid [we do eat it after all] to be certain.

Not that you're proposing to do this, but for the benefit of others reading--never boil rocks; they can explode. The "cracking" was as previously explained due to the temperature difference.

Byron.


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