Not "yea" or "nay", as both Warlocks are correct.
The symbol in question is
the seal of the High Priest. Doktor LaVey wore it and it adorned the front of Magus Gilmore's robe as seen in the promo photos from the 6/6/06 Satanic High Mass.
The symbol was available through the Church of Satan
Emporium several years ago and I bought one, as did a few other Satanists I know. I wear mine in solitary ritual and group rituals I've been the Celebrant in (and sometimes on stage) proudly. If I'm not the Celebrant in a group ritual, I wear my Sigil of Baphomet instead.
The person who made these lowered his quality, so the symbol was taken off the Emporium site, as was everything else this particular person made.
Magus Gilmore used it on the cover of several issues of The Black Flame long before he became High Priest, when Magus LaVey held that position.