2.2 x 2.1 x 2.1 cm. Pecoraite is a relatively rare member of the Serpentine group and was named for Dr. William Thomas Pecora (1913-1972) Director of USGS and student of nickel silicate deposits. This specimen features light green aggregates of Pecoraite on a whitish Calcite (?) matrix. This specimen comes from the collection of noted Colorado geologist, Allen Heyl (for whom Aheylite was named). The piece apparently was obtained by Allen by way of trade from Don Gault.