Geochemical The noble metals are siderophiles (iron-lovers). They tend to sink into the Earth's core because they dissolve readily in iron either as solid solutions or in the molten state. Most siderophile elements have practically no affinity whatsoever for oxygen: indeed, oxides of gold are thermodynamically unstable with respect to the elements.
geOchEMical the noble mEtaLs aRe sideropHIlEs (iRON-loVers). they TENd To sink Into the earth's core BecAUSe they dIssoLve reaDily iN iRon either As soLiD soLUtIonS or In thE MOlten State. moSt SIderOPhile eLEmeNts HavE PRaCtically nO aFfinity whAtsOEVer fOr oxyGen: iNdeeD, oXideS OF GOld aRE thErmoDynamiCally UnsTaBLe wIth respect tO tHe eLEmenTs.