Silicon has a solid density of about 2.33 g/cm3 and a liquid density at melting point of 2.57 g/cm3, so yes, the solid form floats on the melted, but that only happens around 1414 °C (2577 °F).
Germanium floats too.
Tin in it's "grey" allotropic form is lighter than the melted tin, while the "white" allotrope is heavier.
For room temperature liquids, water is quite unique in that way.
Reductionist and proud of it.
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