Table 2. Relative density and refractive index of four Pinaceae essential oils

Botanical name	Relative density (g/mL)	Refractive index (nD²⁰)
Picea koraiensis	0.8969 ± 0.0027^a	1.4720 ± 0.0001^a
Abies nephrolepis	0.8645 ± 0.0002^d	1.4692 ± 0.0002^d
Picea abies	0.8721 ± 0.0002^c	1.4704 ± 0.0002^c
Tsuga sieboldii	0.8743 ± 0.0003^b	1.4709 ± 0.0002^b

All measurements were performed in triplicate; results are mean ± SD.
Mean values with different letters are significantly different at p < 0.05, as analyzed by Tukey’s multiple range test.