I have a few of these types; some don't have the "latticinio" cage, some do. The ones with 2 ribbons can get complicated. But I've never heard them referred to as "tornado." The only ones I know of that are associated with that term are a few (scarce, if not rare) old Germans -- faceted pontil, I think, I'll check at home tonight -- that are generally classified as slags, with all of the white in the interior, quite literally in the shape of a tornado. I don't have one, or a pic of one, but I'll see what I can find . . .