What is "yttriaite-"

Yttriaite-(Y) is an exceedingly rare mineral, a natural form of yttrium oxide, YO. In terms of chemistry it is yttrium-analogue of kangite, arsenolite, avicennite and senarmontite (isometric minerals). Other minerals with the general formula AO include corundum, bismite, bixbyite, eskolaite, hematite, karelianite, sphaerobismoite, tistarite, and valentinite. Yttriaite-(Y) forms tiny inclusions in native tungsten.