शीतोदकीयं पद्माभं कालस्निग्धं वा ॥ कZ_०२.११.५३ ॥
śītodakīyaṃ padmābhaṃ kālasnigdhaṃ vā
‘Śītodakīya’ is lotus-like in appearance, or else dark and glossy.
It signals a recognizable sheen/appearance associated with quality; such cues support rapid field verification without specialized instruments.