Blocks, or non-figural flower frogs, are distinguished by the characteristic of not having a figure on top.
Glass blocks came in two forms:
Peter Christensen's Collection
For multiple views of each flower frog and tips on identification see My Glass Collection.
Clockwise from the figurine: Co-Operative Flint, Beaumont, Japana, Viking, Northwood, and Davidson
Brook's Amazing Colors
Kevin Harper's Collection
Green cloud glass
Orange cloud glass
Amber cloud glass
Amethyst cloud glass
Posy bowls, all cloud glass except for the one that's front and center
320 flower sets
Base with studs to hold flower frog in place
Cloud glass flower frogs
The Parker-Rutland Collection
You can see the full collection on The Parker-Rutland Collection page.
Even clear glass can be beautiful