For those of you who might be wondering about the authenticity of the Apocalypse of Gabriel stone, Yuval Goren has published a chemical analysis of it. "Micromorphologic Examination of the 'Gabriel Revelation' Stone," Israel Exploration Journal 58 (2008) pp. 220-229.
The report indicates that the soil on the inscribed stone originated from the Dead Sea area, particularly east of the Lisan area. There is evidence of calcitic incrustation built up over part of the inscription with no visible signs of unnatural materials. This looks to be the result of the natural process of crystallisation which takes place over time. Since there is no indication of modern treatment of the surface of the stone, it will be necessary that further analyses, preferably dating of the pigment of the inscription, be done in order to conclude that the entire inscription or parts of it were created in antiquity or forged in modernity.