Anandakanda 2.1.75

2.1.75

khaṇḍākhyā caiva tadrūpaṃ vivicya parikalpyate /
śyāmā raktā kharāṅgā ca bhārāḍhyā śyāmikā matā //

and khaṇḍākhyā; its form is determined upon distinguishing [them]:
śyāmikā is considered dark, reddish, rough-textured, and heavy;