Murano Glass Concentric Gold Dust Ruby and Black Amethyst Bowl Set

1950s Murano art glass bowls in dark ruby glass (looks black) with aventurine in a swirling vortex. Hand-made of thick cased glass with stylized rims.  The images below have white reflections interrupting the beautiful aventurine swirl.  There is no white.  These bowls are much more impressive than the images show.  Looks like ruby star dust. No labels or maker's marks.  An example of these bowls is shown on page 91 of 'Circa 50s Glass' by Leslie Pina, and is stated to be Italian (Murano, Venetian) glass but does not give a maker.   The tri-corner bowl measures 8.25"  long and 8.25" at widest, 2.75" tall.  The round bowl with shelled edges measuers 7" wide and 2.75" tall.  Each weighs just under 3 lbs. Both in perfect condition with light bottom-wear around the edges of the seat.  Beautiful matching pair made from the same batch by the same artist.