Gallium metal
The left image contains liquid gallium under very dilute hydrochloric acid in a small test tube, at temperatures at around 25-30 C (77-86 F); it melts at 29.76 C but often supercools. The very dilute acid keeps it shiny and stops it from wetting glass (ordinary liquid gallium readily wets glass). When the test tube (left image) was placed almost horizontally and for many hours at around 20 C (68 F), the metal solidified in an unusual shape on the right image with a crystal at the bottom (the solid metal was then taken out of the test tube and photographed).
Gallium metal
The left image contains liquid gallium under very dilute hydrochloric acid in a small test tube, at temperatures at around 25-30 C (77-86 F); it melts at 29.76 C but often supercools. The very dilute acid keeps it shiny and stops it from wetting glass (ordinary liquid gallium readily wets glass). When the test tube (left image) was placed almost horizontally and for many hours at around 20 C (68 F), the metal solidified in an unusual shape on the right image with a crystal at the bottom (the solid metal was then taken out of the test tube and photographed).