Structural Evolution of Burmese Amber during Petrifaction Based on a Comparison of the Spectral Characteristics of Amber, Copal, and Rosin

Table 2

Raman peak attributions of the amber, copal, and rosin samples.

Group	Saturated or unsaturated	Raman peak (cm^−1)					Evolution of spectral feature
		Burmese amber			Copal	Rosin
		A-1	A-2	A-3
Conjugated unsaturated double bond in carbon chain skeleton C=C	Unsaturated	1660	1646	1653	1662	1649	The peak intensity differs between amber and copal/rosin
Saturated hydrocarbon group CH2	Saturated	2917	2923	2919	2927	2925	—
Carbon-carbon single bond C–C in carbon chain skeleton	Saturated	1442	1436	1440	1442	1433	—