According to Gardner (page 73), the matte finish on Florentia was accomplished by either sandblasting or acid etching.

Scott Hansen

The Collector’s Encyclopedia of American Art Glass by John A. Shuman III at p.21 says “Florentia is exceedingly rare and a unique type of Carder glass found mainly in major museums. On occasion, an example is offered for sale. Manufactured either in the late ’20s or ’30s, there was created within the acid white crystal a soft appearing leaf form. This five-petaled leaf, in green (Jade) or rose (Rosaline), is delicately veined; the points project upwards from the bases of hollow examples, like vases and goblets. On a deep bowl viewed from above, they radiate outward in a circle. Flecks of mica throughout the glass give the added illusion of shimmering morning dew. Existing examples display both the Fleur-de-Lis signature and air traps, ranging from a common nail head to the size of a dime.