The borotellurates are heteropoly anion compounds which have tellurate groups attached to boron atoms.
The first borotellurates to be discovered were the mixed sodium rare earth compounds in 2015.
The borate is in the form BO3, with two oxygen atoms shared with two tellurate TeO6 groups.
[1] Related compounds include boroantimonates, galloborates, borogermanates, borophosphates, boroselenates, boroselenites, and borosulfates.
[2] Borotellurates are formed by heating boric acid, and tellurium dioxide, with metal carbonates or oxides at over 800 °C.