Fontana, a ruby, emerald and diamond brooch, mid 20th century, designed as a pair of songbirds set

Fontana, a ruby, emerald and diamond brooch, mid 20th century, designed as a pair of songbirds set with brilliant-cut diamonds and circular-cut rubies, on a gold tree branch with leaves and berried of carved emeralds and rubies, accented with collet-set brilliant-cut diamonds, mounted in bicoloured gold, length 6cm, signed Fontana, Italian maker's marks, stamped 750