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09 Nov

Microscopic salt and sugar

Posted by Microscopes Specialists

If I ask you “Do you know how sugar and salt look like?”, you’d think that I’m insane, everyone knows how salt and sugar look like. We use them every day in our meals, we know how the taste and look. But what if I ask you another question: “Do you know how salt and sugar look under the microscope?” What would you say? Have you ever seen them so close? If not, then I’ll be very happy to tell you. Take a grain of table salt and a grain of sugar and put both of them under the digital microscope and take a picture. On this picture you will see two types of crystals: bigger ones – decahedrons – this is sugar and round ones – this is salt.
Natural sodium chloride crystals (this is exactly how chemists call our salt in “their language”) have totally different cubic form. Rock salt consists of small crystalls grown together into one solid monolith. Besides salt crystalls we can see various contaminations there, such as other salt crysltals as well as foreign firm elements. For purification of this kind of salt chemists use method, which is called “backboiling”. They dissolve the salt in the boiling water in order to get a saturated solution. When the process ends, there will be salt left on the bottom, which didn’t dissolve. Then the solution needs to be separated from it’s sediment and be cooled off. So, this white salt, which we got using this “backboiling” method has the right shape of crystals – cubic.
The table salt on the contrary has round shaped crystals. It happens because after the backboiling process the salt was milled and cubic sides were obliterated.
Sucrose crystalls, which we out of habit call sugar, have very interesting shape – two wide rectangular sides and each side is surrounded by four narrow inclined sides. In this way, the crystall consists of two truncated pyramids, connected at the base. Correlation between the crystall width and the size of big sides depends on the plant if was made from. Crystal form of beet sugar tends to be of a cubic form, cane-sugar crystalls have the shape of plates.

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