Core formation resolves Earth's siderophile excess without a late veneer.

Highly siderophile elements (HSEs) are expected to be extensively depleted in the mantle due to their affinity for metal during core formation. Yet, their abundances in the mantle far exceed the predictions based on low pressure and low temperature partitioning experiments. In addition, all HSEs are present in similar chondritic relative proportion in the mantle. This has traditionally been attributed to the late accretion of chondritic material, the late veneer. We present laser-heated diamond anvil cell experiments that quantify the partitioning behavior of five HSEs (rhenium, osmium, iridium, palladium, and gold) under pressure-temperature conditions directly relevant to early Earth's magma ocean. Our results demonstrate a substantial decrease in metal-silicate partition coefficients with increasing temperature. Multistage accretion models reproduce the observed HSE abundances and ratios in the mantle without invoking a late veneer. This resolves the longstanding paradox of HSEs excess' in the mantle and suggests that the delivery of volatile compounds to the young Earth is primarily explained by early accretion and differentiation processes.