Name	Specific Gravity	Smallest RI	Largest RI	Birefringence	Hardness
calcite	2.72	1.486	1.658	0.172	3
magnesite	2.98	1.509	1.7	0.17	4
rhodochrosite	3.7	1.597	1.816	0.219	3.7
siderite	3.96	1.635	1.875	0.24	4.3
dolomite	2.86	1.5	1.679	0.179	3.7
aragonite	2.94	1.53	1.685	0.155	3.7
strontianite	3.72	1.518	1.667	0.15	3.5
witherite	4.3	1.529	1.677	.	3.3
cerussite	6.57	1.803	2.076	0.275	3
azurite	3.77	1.73	1.838	0.108	3.7
smithsonite	4.43	1625	1.85	0.227	4.2