ALLANITE - Here we have the Calcium Aluminum Iron Silicate Hydroxide known as Allanite, Ca(Ce,Th)(Fe,Mg)Al2[O/OH/SiO4/Si2O7] a rare earth mineral. Tabular Allanite crystal from Oso Township, Frontenac Co., Ontario, Canada. Size is 3.5cm (1-3/8" wide) x 3cm (1-1/4" deep) x 0.5cm (1/4" thick) Item 0866. Nice specimen.