28.3495231 / 4 ≠ 7.2

as said, density plays a heavy roll but i'd say it's just a gram or so under from that pic, although i don't really know american coin sizes to use em as a reference
And remember, a dealers 8th will rarely be an actual 8th, i don't understand why dealers still use the terminology when it's near guaranteed they're selling by the gram, an eighth where i'm at is 2 grams, not 3.5, yet they'll still tell you it's an eighth, pikey shits.