resolidification
They found that the rock did resolidify within a few weeks.
Place the vial in iced water, wait for the contents to resolidify, then heat the water to 30C, at which point the contents will melt again.
The gel was melted on a microscope slide and covered with a cover slip; it was then re-solidified during cooling to fix the sample.

SMART Vocabulary: related words and phrases

Physical & chemical processes
absorbable
absorptive
absorptive capacity
absorptivity
acidification
endothermic reaction
excitability
excitation
excite
exergonic
exothermic
exothermic reaction
impregnate
re-emit
reabsorb
react
reboil
recondense
scald
vaporize