Victorian-era Loetz enameled platter, ca. 189os

Documentation is sparse on Loetz art glass of this era, but I have seen this decor on 1890s marmoriertes (marbled) glass made by Loetz. This is a large platter - about 11 inches across. Hand-tooled and fire polished rim, with a ground and polished pontil. There appear to be remnants of a decor marking, but it is too far gone to read, even under magnification. I believe this color is heliotrope, which is a pinkish purple.