Angle and History

The one-hundred-and-fifty-degree relation is discussed in Hellenistic sources as an aversion, a non-aspect, and its promotion to an active minor aspect belongs to the broader harmonic current that followed Johannes Kepler's Harmonices Mundi of 1619, though Kepler's own new aspects are usually reckoned as the fivefold and eightfold divisions, the quintile family and the semi-square family, rather than the quincunx specifically, so later astrologers, rather than Kepler himself, are the more exact source for its adoption.

Chart software and modern textbooks nonetheless group it with his reform for convenience. Its glyph, unlike several of the other minor aspects, was given a dedicated place in the Unicode Standard: QUINCUNX at U+26BB in the Miscellaneous Symbols block, drawn as the intersecting lines taken from the inner angles of the lower half of a hexagon, in effect the sextile sign turned and halved, a construction that visually ties the quincunx back to the sextile geometry even though the two aspects have almost nothing else in common. Its codepoint sits in the character table close to the sesqui-quadrate and just after the semi-sextile, a run of minor-aspect signs added to the Miscellaneous Symbols block well after the core set of planetary and classical aspect glyphs that had been present since the standard's earliest releases in the 1990s.