Yod (astrology)
Yod is the astrological formation of any of the 10 planets and luminaries connected by two 150 degree angles (called inconjunct or quincunx) to a 60 degree angle called a sextile. Furthermore, to qualify as a Yod formation, it must have a very tight 'orb of influence', meaning that the allowable orbs for the this aspect can be no more than 3 degrees.
While the sextile is an inherently harmonious aspect, the quincunx is unrelated to either of the sextile planets. It shares neither polarity - Yin/assertive or yang/receptive, astrological element - fire, water, air, or earth, or modality - cardinal, fixed, or mutable.
Meaning
Astrology has different views regarding the interpretation of the Yod. It's traditionally been known as a minor pattern, but more recently, has been gaining interest. One theory gaining attention is that the Yod reflects the 1-6-8 sign pattern of the zodiac.
Hypothetical example
As an example of the 1-6-8 Yod interpretation would be with Mars at 11" Aries in a quincunx angle to Mercury at 11° Virgo and the Sun at 11° Scorpio. The confusion arises between the impulsive and energetic character of Aries interacting with the analytical and careful character of Virgo, and the intensity and mystery of Scorpio. The lack of commonality of Mars with the two sextile planets (Virgo and Scorpio in this example) illustrates how the Yod triggers an irritating situation, yet one that pulls the individual to discover completely new pathways in one's life. Some natives will ignore it altogether, while others are fascinated by the strangeness and attempt to adapt so that they can explore this complex ground.
Sometimes with initiative and fortitude to overcome the confusion created by the yod, great rewards can result. It is a not uncommon element in the charts of those who overcome limitations in early life to later then become especially known for their unique contributions to their chosen fields of interest.
An alternate perspective is that a yod is an aspect that indicates some kind of dramatic event, or 'finger of fate'; Yods represent extraordinary powers available for good or ill; it is largely a matter of how the individual uses the energy, and whether the planets forming the crucial aspects are in any way harmonious.
Golden yod
Related to the yod, though much less noticed, is the golden yod. A golden Yod occurs when one planet forms biquintiles (144° aspect) to two others separated by a quintile(72° aspect). Because these aspects are seen as beneficial, the golden yod is seen as reflecting characteristics acquired by the person whose chart contains it. The few astrologers who have studied it regard it as an extremely creatively charged aspect good for artistic skill, especially as quintiles and biquintiles are frequently linked with Neptune. An example of a golden Yod would be with the Sun at 20° Cancer, Uranus at 8° Taurus and Jupiter at 14° Sagittarius.