Refractory Element Trends on the Two‐Dimensional Four‐Component Plot

ABSTRACT High‐temperature fractionation of refractory lithophile elements is known to shape both stellar abundances and the composition of primitive planetary materials. Here, we show that planet‐hosting stars, barren stars, chondrites and chondrule/matrix components occupy a common axis of variation in four‐component space, highlighting the shared process governing their Mg‐Si‐Ca‐Al ratios across cosmic environments. By introducing a novel ‘2–4 plot’, which encodes the fourth dimension as a line orientation in two‐dimensional space, we consolidate these data into a single diagram and reveal subtler compositional trends that conventional diagrams might miss. In this compilation, bulk chondrites overlap the planet‐hosting stars, while the most outlying stellar abundances occur chiefly among barren stars, consistent with sampling, detection and/or uncertainty bias. This unified view of four‐component systems can help discriminate evolutionary tracks and better anticipate the mineralogical outcomes in nascent planetary systems. The diagram could facilitate discrimination and trend detection in other four‐component systems.