Abstract: Methods and compositions for the treatment of subterranean formations, and more specifically, treatment fluids containing vitrified shale and methods of using these treatment fluids in subterranean formations, are provided. A method of displacing a fluid in a wellbore comprises providing a wellbore having a first fluid disposed therein; and placing a second fluid into the wellbore to at least partially displace the first fluid therefrom; wherein the second fluid comprises a base liquid; vitrified shale; a clay weighting agent present in the range of about 5% to about 20% by weight of the second fluid; and a viscosifying agent present in the range of about 1% to about 10% by weight of the second fluid.