Alundum Extraction Thimbles

Extraction thimbles remain very uniform in weight. Preferable to paper thimbles as they can be used indefinitely and permit the ignition of the extracted residue without removing the material from the thimble. Place thimble in a strong solution of acid for a short time period in order to clean and then ignite to constant weight in usual way. Fine grade fused alumina material (91% alumina oxide).