Syblle Jargstort says in her book "Baubles, Buttons and Beads" (Schiffer) that saphiret glass was created in the 19th century. The 2 tone effect - varying from brick red to sapphire blue - was made by mixing gold to a basic sapphire blue glass. She gives examples from Gablonz up to the 1930's. It was expensive to make.
Diane de Mango - illusionjewels.com - says that later stones - which she calls sapharine - were made in Germany. They are not as distinctive as the older ones.
The examples in the picture are from my own collection and the dates vary - I particularly like the necklace. Saphiret stones are difficult to photograph - do look at other examples on the internet.