Gem News International Gems & Gemology, Fall 2013, Vol. 49, No. 3

Amber with Insect-Bearing Filling


Figure 1. The beads in this strand of prayer beads measure approximately 12 mm in diameter. Photo by Sutas Singbamroong.
We recently tested an interesting strand of Islamic prayer beads resembling amber (figure 1). It consisted of 33 round yellow beads approximately 12 mm in diameter, two oval-shaped separators, and a fancy-shaped link. It was purchased as amber from a dealer at an annual festival in Dubai.

The round beads contained dark brown plant debris and a variety of insects: ants, flies, and spiders, all in good condition. The beads’ surfaces also featured noticeable circular zones, and when exposed to long-wave UV radiation, they displayed a weak, blue fluorescence and distinctive chalky blue circular areas (figure 2). The beads were inert to short-wave UV radiation.

Figure 2. When exposed to long-wave UV radiation, these beads displayed weak blue fluorescence and distinct, chalky blue circular areas. Photo by Sutas Singbamroong.
These features were similar to those of copal filled with plastic (Winter 2010 GNI, pp. 326–328). We obtained spot RI readings of 1.52 on the circular zones and 1.54 elsewhere. Next, we analyzed the strand using Raman spectroscopy with a 785 nm diode laser. The separator link and the main portion of the beads showed peaks between 1434 and 1644 cm–1, consistent with amber. The circular areas’ strong bands at 623, 807, 1100, and 1599 cm–1 were consistent with epoxy resin (figure 3).

Figure 3. Raman spectra collected from the main portion of the beads were consistent with amber, whereas the circular areas indicated an epoxy resin.
Microscopic examination with immersion in water indicated that all the round beads had been cored and filled (figure 4). The beads were identified as amber filled with colorless to light yellow plastic to imitate insect-bearing amber.

Figure 4. Microscopic observation with immersion in water clearly indicated that these amber beads had been cored and filled with a colorless to light yellow plastic containing insects. Photomicrographs by Sutas Singbamroong; magnified approximately 10×.

Sutas Singbamroong (sssutas@dm.gov.ae), Nazar Ahmed, and Hassan Al Marzooqi are analysts with the Gemstone Unit of the Dubai Central Laboratory in Dubai, United Arab Emirates.