[Petrochemicals (OP)]

I have some liquid which I am assuming to be water as it is not oily, has no scent, has the same viscosity and have ruled out anything else. It is only a few drops but it is on some salt from a bag of salt and grit that is used for pavements in the winter. As I said, it is only a few small drops  but it doesn't seem to wish to evaporate, it has been there for at least 12 hours in a hot environment.

[paul cotter]

Hi Petro, I typed out a detailed response to your query and when I tried to post it came back as an error but it gave me the option of reposting-- I tried this to be accused of double posting, AAGH!!. I'm tired, have been travelling and i'm not doing this again, tonight. If no other answers arrive tomorrow I'll try again. 

[Bored chemist]

Could there be calcium or magnesium  chloride in there?

[evan_au]

May be hygroscopic salts in there - they absorb moisture from the atmosphere (which BC was alluding to).
https://en.wikipedia.org/wiki/Hygroscopy

In extreme cases, this becomes "deliquescence" - these compounds absorb water from the atmosphere, and dissolve in the extracted water.
https://en.wikipedia.org/wiki/Hygroscopy#Deliquescence

[paul cotter]

Thanks, Evan_au. As I explained above I answered similarly in a more verbose but most likely less clear answer that evaporated.

[Petrochemicals (OP)]

It has evaporated finally

Could there be calcium or magnesium  chloride in there?

I do not know, it's rock salt, mined probably so there may be anything in it, plus any additives.

May be hygroscopic salts in there - they absorb moisture from the atmosphere (which BC was alluding to).
https://en.wikipedia.org/wiki/Hygroscopy

In extreme cases, this becomes "deliquescence" - these compounds absorb water from the atmosphere, and dissolve in the extracted water.
https://en.wikipedia.org/wiki/Hygroscopy#Deliquescence

Mmm, it may be something like this, I believe it may have been liquid water but it persisted.

Thanks, Evan_au. As I explained above I answered similarly in a more verbose but most likely less clear answer that evaporated.

Thanks for trying.