aphthitaliteMin.|æfˈθɪtəlaɪt|[mod.f.(1835)Gr.ἄϕθιτ-ος undecaying + λίθος stone; so called because unalterable in the air (Dana).]A native sulphate of potash found upon lava at Vesuvius; also called Vesuvian Salt, Aphthalose, Arcanite, and Glaserite.