  Recently, I reported the discovery of a new fundamental relationship of the
major elements (Fe, Mg, Si) of chondrites that admits the possibility that
ordinary chondrite meteorites are derived from two components, a relatively
oxidized and undifferentiated, primitive component and a somewhat
differentiated, planetary component, with oxidation state like the highly
reduced enstatite chondrites, which I suggested was identical to Mercury's
complement of lost elements. Subsequently, on the basis of that relationship, I
derived expressions, as a function of the mass of planet Mercury and the mass
of its core, to estimate the mass of Mercury's lost elements, the mass of
Mercury's alloy and rock protoplanetary core, and the mass of Mercury's gaseous
protoplanet. Here, on the basis of the supposition that Mercury's complement of
lost elements is in fact identical to the planetary component of ordinary
chondrite formation, I estimate, as a function of Mercury's core mass, the
total mass of ordinary chondrite matter originally present in the Solar System.
Although Mercury's mass is well known, its core mass is not, being widely
believed to be in the range of 70 to 80 percent of the planet mass. For a core
mass of 75 percent, the calculated total mass of ordinary chondrite matter
originally present in the Solar System amounts to 1.83E24 kg, about 5.5 times
the mass of Mercury. That amount of mass is insufficient in itself to form a
planet as massive as the Earth, but may have contributed significantly to the
formation of Mars, as well as adding to the veneer of other planets, including
the Earth. Presently, only about 0.1 percent of that mass remains in the
asteroid belt.
