Sumatra Blue Amber (Sinamar Fm., ~30 Ma)

Small (5-8g) partial nodules of raw blue amber from the east flank of the Bukit Barisan range of West Sumatra. These pieces are clear as glass, and fluoresce very nicely under a 140 lm LED light. *This Sumatra material (and Indonesian amber in general) is believed to have been produced by a parent tree belonging to the Dipterocarpaceae family; it's spectroscopic signature is also incredibly similar to Bitterfeld amber (also produced by a dipterocarp source tree). **This blue amber's particular locality is part of the Sinamar Fm., and the layers containing the resin are dated to be approximately 30 Ma (Oligocene, mid-Rupelian); the amber-bearing strata of this formation is located at a depth of approximately 32-39 m, and is composed of hard, banded coal (sub-divided into two layers of slightly different grades, 2.5m and 4.5m thick). I have 15 pieces, and these are the ones I haven't yet pre-formed. The piece in the upper-right corner is pre-formed (diamond needle files), and it is ready for increasing grades of sandpaper (240-3000 grit), and a final polish with a denim cloth and polishing compound (ZAM).