Robert James FGA, GG, President of International School of Gemology, reported for a difficult for identification synthetic moissanite with optical effect resembling chatoyancy.
Report informs that all of the traditional diamond testers showed this as a diamond. Due to the high concentration of inclusions, the usually diagnostic doubling of facet junctions seen in synthetic moissanite were virtually impossible to see without microscope.
The mineral is identified by a microscope 90x study and with Raman Spectroscopy.
One of the conclusions of the author of this study is to not trust those diamond testers on the market that are supposed to separate diamond from synthetic moissanite.
The report can be found here