జ్యోతిషంలో పిల్లి కన్ను (వైదూర్యం): కేతు రాయి — ఆధ్యాత్మిక విముక్తి రత్నం

Vaidurya as Ketu Ratna — Chhaya Graha Nature and Classical Text Standards

Vaidurya (Cat's Eye Chrysoberyl, also called Lehsunia or Ketu-mani) is the designated ratna of Ketu (south lunar node) in Vedic Jyotish — the second Chhaya Graha (shadow planet) representing moksha (spiritual liberation), past-life karmic residue (prarabdha), occult perception, asceticism, and sudden, unexpected change. The Brihat Parashara Hora Shastra describes Ketu as headless (being the severed body of the demon Svarbhanu), analytic, separative, and powerfully karmic — and its ratna reflects this nature. The Ratna Pariksha specifies that an authentic Vaidurya must display a sharp, distinct chatoyant band (the 'cat's eye' or Sutra-rekha) precisely centred across the stone when illuminated by a single overhead light source — this band, caused by parallel needle-like inclusions of rutile or hollow tubes within the chrysoberyl crystal, is the gem's defining and authenticating feature. The best Vaidurya originates from Sri Lanka (Ceylon) and Brazil, with Sri Lankan material most prized in Jyotish tradition for its golden-green to honey-brown colour range. The stone must be cabochon-cut (not faceted, as chatoyancy is visible only in cabochon form), with the cat's eye band perfectly centred and crisp. A minimum of five rattis is conventional, with eight to eleven rattis for Ketu Mahadasha. Colour preference varies by lineage: some prescribe honey-yellow, others prefer grey-green or milk-and-honey bicolour (called milk and honey Cat's Eye), considered especially auspicious in classical texts.