There is a crown of lustrous green on the head, while the wings and tail are glossed blue.

In many regions, the throat area is iridescent reddish-purple; however, moving northward it shifts towards a bluish sparkle (Moluccas and Kai Islands).

[4] The song and sound is a rapid, sweet cadence lasting 1.5-4 seconds in duration.

It consists of single or a series of high-pitched sibilant notes; rapid fire double notes, one is higher than the other, clear hallow peep; a rapid slurred, shrill zi-zi-zi-zi[4]closing with the flight call pit-pit-pit.

[4] The black sunbird was recorded laying in August and September in Sulawesi, March and May-January on islands of Papua New Guinea.