This is not required information for students of EPS 2

GEMSTONE	RI	READ THROUGH	DISPERSION	COLOR ON PAVILLION	HARDNESS	SPECIFIC GRAVITY
Diamond	2.417	None, if properly cut	0.044	Orange or blue on a few faces	10	3.52
Strontium nitrate	2.409	None, of properly cut	0.190	Spectral colors, widespread	5-6	5.13
Synthetic cubic zirconia	2.15	Slight	0.060	Orange over most of pavilion	8.5	5.95
Gadolinium gallium garnet	1.970	Moderate	0.045	None, or orange over most of pavilion	6.5	7.05
Yttrium aluminum garnet	1.833	Strong	0.028	None, or blue over most of the pavilion	8.5	4.55
Synthetic rutile	2.616-2.903	None	0.330	Various spectral colors widespread	6-6.5	4.26
Zircon	1.925-1.984	Moderate	0.038	Blue over most of the pavilion; may exhibit orange	7.5	4.70
Synthetic sapphire or corundum	1.762-1.770	Very strong	0.018	Blue over most of pavilion	9	4.00
Synthetic spinel	1.730	Very strong	0.020	Blue over most of pavilion	8	3.64
Glass	1.48-1.70	Extreme	0.009-0.098 (usually 0.38)	Variable	5-6.5	2.30-4.50