# Q: Simple Chemistry Exp. w/Odd Results **URL:** \ **Category:** Factual Questions\ **Created:** [October 4, 2004, 1:24pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450 "2004-10-04T13:24:08Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [October 4, 2004, 1:24pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450/1 "2004-10-04T13:24:08Z")
Homeschooling my 5 yr old, we have been doing simple experiments with tap water. One such experiment involved the evaporation of water from an open-mouthed jar at room temp. For curiosity sake, a second jar was placed beside it with a solution of salt water. (a third jar of tap water with a lid was used as a control.) While the tap water is evaporating as expected, the salt water is evaporating equally well. However, crystals of salt (presumably) have formed on the water’s surface in the shape of tiny snowflakes. The tap water has nothing floating on its surface, so it is not dust, for example. If this is salt, I thought the lattice of a salt crystal (NaCl) could only form in a cubical geometry. Can someone explain what is happening here? Does NaCl have an alternate lattice structure…such as that typical of the transitional elements? Thanks, - Jinx ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [October 4, 2004, 1:32pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450/2 "2004-10-04T13:32:34Z")
Perhaps you’ve considered that salt was not the only thing dissolved in your water samples. The other minerals in the tap water could have affected the crystal shape. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [October 4, 2004, 3:22pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450/3 "2004-10-04T15:22:01Z")
> [@AskNott](#): > > Perhaps you’ve considered that salt was not the only thing dissolved in your water samples. The other minerals in the tap water could have affected the crystal shape. Yes, that thought crossed my mind. My first thought was that those same impurities are present in the sample of tap water, too. But, perhaps the NaCl crystals are becoming doped as they settle out? The next step is to repeat with distilled water, and see what forms… - Jinx ---
**Author:** ![chaoticbear](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@chaoticbear](https://boards.straightdope.com/u/chaoticbear)\ **Post date:** [October 4, 2004, 5:34pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450/4 "2004-10-04T17:34:53Z")
I think that it would have something to do with the salt forming in cubes on a smaller level than the snowflake pattern you see. The salt _is_ forming cubes, just at a smaller level. Like a snowflake made of cubes. Take what I said with a grain of salt, though… I’m not quite sure it explains it. I think so, though. ---
**Author:** ![Punoqllads](https://avatars.discourse-cdn.com/v4/letter/p/d2c977/32.png) [@Punoqllads](https://boards.straightdope.com/u/Punoqllads)\ **Post date:** [October 4, 2004, 5:55pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450/5 "2004-10-04T17:55:58Z")
A cube turned point-up has a hexagonal profile. Maybe that’s what’s happening. ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [October 4, 2004, 8:29pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450/6 "2004-10-04T20:29:29Z")
Just how much salt did you put in the water. Sounds as if there was enough to make a saturated solution. This would cause supersaturation or the deposit of salt crystals on the sides of the glass jar. Never have seen floating crystal such as you describe. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [October 4, 2004, 10:19pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450/7 "2004-10-04T22:19:20Z")
You may have just made an artificial version of [fleur de sel](http://www.ac-rennes.fr/pedagogie/svt/travaux/sel/sel122.htm), which is the crust that forms on the top of seawater when it’s evaporated, and is sold for exorbitant prices. Here’s a rough translation of the link; there’s a bit of technical vocabulary that I can’t translate: > [@](#): > > [first caption] The collection of fleur de sel by the (salt-collector?) is done with a _lousse_, a wide thin chestnut-wood plank making a 30-degree angle with the handle in order to pemit the tool to be moved on the surface of the (water?) Fleur de sel is composed of fine, light crystals floating on the surface. > > [second caption] Above, we see the appearance of fleur de sel (right) compared with that of “large salt” (left.) If we look closer at the fleur de sel (below), we see that the cristals are all about 0.2 to 1.0 mm in size. It sometimes has a pinkish tint, due to the growth of a microscopic red alga _Dunaliella_ which gives it the scent of violets. ---
**Author:** ![bizzwire](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@bizzwire](https://boards.straightdope.com/u/bizzwire)\ **Post date:** [October 4, 2004, 10:22pm UTC](https://boards.straightdope.com/t/q-simple-chemistry-exp-w-odd-results/267450/8 "2004-10-04T22:22:39Z")
Just a tought: could you be creating some sort of coordination complex of salt and dissolved metals, such as calcium?