[3][4] The Topazes group contains some of the largest hummingbirds in the family, adult males measuring up to 23 cm and weighing up to 12 g.[3][5] Topazes as a group are estimated to have diverged as a separate lineage from all other hummingbirds around 21.5 Ma, whereas the most recent common ancestor of Topaza and Florisuga lived approximately 19 Ma.
Neither intermediate forms nor hybrids have been reported, and no specimens have been found that showed any combination of the characteristics of the two taxa.
[6] The Amazon River seems to have played a part in keeping the lineages distinct, inhibiting gene flow and promoting the speciation.
[6][8] Males of these brilliantly marked hummingbirds have a back, lower breast, upperwing-coverts, and outer webs of the innermost two remiges that are shining orange-red, becoming more orange on the belly, shading over the rump into the yellow-green/green uppertail-coverts.
The top and sides of the head are velvet black, with an iridescent green and orange red throat and a thick, decurved and a rather short bill (about 25 mm (0.98 in).
The upper and under-tail coverts have orange highlights in the males, as opposed to blue-green in the females, and are somewhat lengthened and loose-webbed.
[1][12][13] Its natural habitat is subtropical or tropical moist lowland forest, at an elevation up to 500 metres (1,600 ft) above sea level.
[1] They are encountered high in the canopy and prefer the edges of forests and clearings near water, and are often seen close to river banks.