CERMET is a portmanteau of “ceramic” and “metal.” So by this alone it should be easy to tell that when a watchmaker finds a use for this composite — as Seiko now has — the resulting part made from such material would be a tough one. In the newly announced pair of Seiko Prospex LX Spring Drive models (each is limited to only 200 examples), cermet has found its way on the watches’ bezel inserts.

But Seiko says cermet offers up another advantage; the material allows for a kind of luster that appears like the surface of water. Seiko added to this by coloring the new watches’ unidirectional rotating bezels in either violet or platinum. Getting the luster of the finished product, according to the brand, would not have been possible with conventional ceramic.

The SNR041J1 is the piece rendered in violet. Its bezel insert color, in true Seiko purple prose, is described as evoking the “sea illuminated by the sun at dawn.” This bezel insert is then matched to a dark brown dial that in photos appear to have a faint sunray finish, and a second hand adorned with “gilt.” A steel case with Zaratsu-polished surfaces and a steel bracelet complete this watch’s look.

The SNR043J1 wears a darker palette because of its black case and black silicone strap. Its cermet bezel insert in platinum color, Seiko says, supposedly appears like the “flickering reflections on the sea from the light of the moon floating in the night sky.” Complementing the bezel is a charcoal dial, also with a seeming sunray finish, and the gold-color touch on the second hand.

The cases for both new Prospex LX watches are taken from the line’s pieces inspired by Seiko’s original Professional Diver’s timepiece from 1968. And the Prospex LX is a genuine professional diver’s timepiece, boasting of water resistance to a saturation diving depth of 300 meters, a screw-down crown, a screw-in caseback, domed crystal and luminescent markers and hands. The clasps used for both the cermet Prospex LX watches have push-button, diver-adjusted mechanisms. Engraved on the caseback of both models are “Limited Edition” and the serial number 001/200-200/200.

As declared on the watches’ dials, the SNR041J1 and SNR043J1 are powered by Seiko’s Spring Drive — in this case the cal. 5R65, a self-winding, 30-jewel movement whose second hand glides, rather than tick, around the dial, and which incorporates a quartz crystal oscillator for more accurate timekeeping. It is reckoned to gain or lose no more than half-a-second a day, or plus/minus 15 seconds in the course of a month. Its 72-hour power reserve can be monitored via a meter on the watches’ dials.

Both the SNR041J1 and SNR043J1 will arrive in Seiko retail shops in November.