Color Guide: Strong yellow color is ideal. Light to medium lemon yellow is acceptable and the standard for unheated yellow sapphires.
Clarity Guide: Eye-flawless is best for Vedic Astrology. Minimum acceptable clarity is VVS2-VS1, or very insignificant inclusions with no black spots. Light “feathers,” or subtle streaks of rutile silk, are not only acceptable but valuable confirmation that the gemstone is unheated. This does not hinder Jyotish properties.
Shape Guide: Oval, cushion, radiant, and emerald cuts are the most common. Round yellow sapphires can be sourced at a slightly higher cost since more material is cut away to make the shape.
Size Guide: 2 carats is considered the minimum weight for Vedic Astrology, though this is approximate and a 1.9ct yellow sapphire will still work. 3+ carats is more powerful. 5+ carats is extremely powerful in this quality.
Treatment Guide: Yellow Sapphires should always be unheated and untreated to receive Jyotish effect. Gems should only be purchased from a reliable source with laboratory certification or written guarantee of lack of treatment.
Avoid: Standard heating, beryllium diffusion, irradiation, synthetic and lab-grown gems, sapphires with poor cuts, and significant eye-visible inclusions.