I had accidentally broken a thermometer against my computer screen, resulting in the splash of the silvery substance seen below:

enter image description here

I cannot remember whether the thermometer is a mercury-free thermometer, and was wondering if you could help with identification of the substance given the following information:

  1. This picture was taken about 1-2 minutes after the initial spill
  2. The temperature of the room was around 70 degrees F.. at most 80 degrees
  3. The silvery substance clung to the screen as shown.
  4. Small bits of the silvery substance seeped into the computer. However, it was fully functional in the few instances I have used it

Any suggestions or additional follow up questions would be much appreciated. Thanks!

  • 2
    $\begingroup$ How can you accidentally break a thermometer on the screen of your computer? Next time hang is on a wall. $\endgroup$
    – ParaH2
    Jul 18, 2017 at 21:06
  • 1
    $\begingroup$ It was the type where you put it in under your arm to measure your temperature. I was shaking it, lost grip, and had it splash against the screen. $\endgroup$
    – daspianist
    Jul 18, 2017 at 21:12
  • 6
    $\begingroup$ I've never seen gallistan, the alloy used in gallium thermometers, but that just doesn't look like mercury to me. If I were really certain though, I'd have make this a formal answer ;) $\endgroup$
    – airhuff
    Jul 18, 2017 at 21:16
  • $\begingroup$ By the way, you have probably destroyed the casing of your computer. Gallium (not sure about the exact alloy used in thermometers, but it contains a lot of gallium) will destroy aluminium.You might not notice it immediately, but the structural integrity of the case will eventually cease to exist. Unless you got it off the case very quickly. $\endgroup$
    – matt_black
    Jul 18, 2017 at 23:54
  • 1
    $\begingroup$ Keep Gallium off your aluminium objects. It amalgamates with it and it's even able to penetrate the oxide film. The result is an alloy of gallium and aluminum. $\endgroup$
    – skan
    Apr 12, 2019 at 19:46

1 Answer 1


Gallium, and Galinstan have the ability to wet glass, while mercury does not.

So it's most probably gallium (or Galinstan).

  • $\begingroup$ Ah - I definitely encountered the wetting glass issue when cleaning. Thanks for this $\endgroup$
    – daspianist
    Jul 18, 2017 at 21:26
  • 3
    $\begingroup$ @daspianist Either way I would get rid of the substance from the body of your MBP. Anodized layer ideally should protect aluminium, but theoretically gallium readily dissolved aluminium. $\endgroup$
    – andselisk
    Jul 18, 2017 at 22:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.