Wanted High density Liquid For suspension of Solids

Main Question or Discussion Point

Hello
I want to suspend, or really have the sinking effect be slow, different kinds of rocks/ gem stones in a jar. So i don't really know where to start. I want something easy to get, clear, not toxic.
I'm going to start with something like corn sryup and see what it looks like. But if anyone has any other ideas i would love to hear them.

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If you want a slow sinking effect you need a liquid with high viscosity, not with high density. You can probably find polymer solutions that have a viscosity that varies very strongly with temperature, that way you can "tune" how fast the rock sinks.

A (very) high density liquid would allow your rocks to float. Liquid mercury would probably do the trick, but it is toxic and not exactly clear.

Chestermiller
Mentor
Hello
I want to suspend, or really have the sinking effect be slow, different kinds of rocks/ gem stones in a jar. So i don't really know where to start. I want something easy to get, clear, not toxic.
I'm going to start with something like corn sryup and see what it looks like. But if anyone has any other ideas i would love to hear them.
Corn syrup is a good choice. It is about 100000 times as viscous as water.

Chet

Gold Member
To be fair, a high-density fluid would work, too. It would just be more difficult to find, especially clear in color.

To be fair, a high-density fluid would work, too. It would just be more difficult to find, especially clear in color.
You can try solutions of various salts in water.

The heaviest seems to be zinc chloride, you can dissolve 4.23 kg in a liter of water. It's rather corrosive and toxic however.
You can dissolve 1.89 kg/l of caesium chloride, wich doesn't have any health problems.

Gold Member
You can try solutions of various salts in water.

The heaviest seems to be zinc chloride, you can dissolve 4.23 kg in a liter of water. It's rather corrosive and toxic however.
You can dissolve 1.89 kg/l of caesium chloride, wich doesn't have any health problems.
Still, it's nowhere near the density of a rock, so such an object would still sink rather quickly.

Various companies sell heavy liquids for separating minerals by density (google "heavy liquid" to find them). The densities of these liquids range from 2 to 4ish. Many of them are quite expensive. Many are damaging to the environment and require careful handling and proper disposal.

Awesome... Good to know about the difference between high density and viscosity that helps. I don't what the rocks to be floating. I real was trying to get a suspended kind of effect in order to display some specimens in a unique way. You all have been real helpful thank you.
Also here's a follow up question does a liquid's density have a direct effect on its viscosity?

SteamKing
Staff Emeritus
Homework Helper
Density affects kinematic viscosity. Dynamic viscosity is another thing.

Ok interesting.. corn syrup offered little resistance. ..

Chestermiller
Mentor
Ok interesting.. corn syrup offered little resistance. ..
Here's another idea. Try Jello. Just wait until it sets some before adding the rocks.

Chet

Granite has a density of ~2.7g/cm^3, so dissolving >1.7kg of a salt would make the solution more dense than a granite rock.
Other minerals may have different density, most seem to be more dense - pyrite is already up at 4.9g/cm^3.