The fact is that Mercury does not have a dense atmosphere, therefore it is almost defenseless against the impacts of celestial bodies. In addition, their traces remain on the surface of the planet for a long time. Interestingly, the energy of such impacts seems to be sufficient for some of the carbon present on the surface in the form of graphite to turn into diamond crystals.
Computer modeling was based on the fact that the 25-kilometer crust of Mercury contains a layer of graphite for 300 meters. Over 4.5 billion years, up to a third of this amount could turn into diamonds. As a result, Mercury, in principle, can contain more crystals than the Earth – 16 quadrillion tons.