The Arskartor beryl deposit is made up of fine albitized muscovite granite (γ(1-1)5，γ(1-2)5)，pegmatite and beryl ore zone. The muscovite granite is a cupola. dipping outward. The pegmatite is of the simple type which can be divided from outer part to inner into pegnlatitic altered granite, altered pegmatite and quartz core. The beryl ore zone, characterized by comb, brecciated and banded structures as well as pegmatitic thetexture, lies in a periclinal structure on the northeast of the cupola, and is controlled by a tension-torsion fault. Following are some mineralogical characteristics of the beryls and the aquamarines; Chemical analyses indicate that the colour and the relatively good trans- parency of the azure and dark blue beryls are related to the fairly low con- tent of alkali metals in the Be clusters, and that the azure beryl is high in Cr, Sr, Pb and Zn, while the darlc blue beryl has high V and somewhat higher Cr and Rb. Temperature measurements of inclusions , in beryls suggest that the deposit belongs to pegmatitic-pneumatolytic-hypothermal-mesothermal type (the aquamarines formed at high-medium temperatures)，with the formation pressure being 650士50 atm. The aquamarines contain water molecules in their textural pores, and have hardness of 7.7, refraction indexes Nc=1.57A3, No= 1.5788 and specific gravity 2.73.