Orange and Brown Gemstones <

Gemstone	Crystal System	Density	Hardness	Refractive index	Treatments
Agate	microcrystalline	2.66	6.5-7.0	1.544-1.553	dying
Amber	amorphous	1.08	2.0-2.5	1.54	heating, oiling, reconstitution
Chalcedony	microcrystalline	2.66	7	1.544-1.553	dying
Chrysoberyl	orthorhombic	3.72	8.5	1.746-1.755	none
Coral	trigonal	2.65	3.5-4.0	1.486-1.658	dying
Diamond	cubic	3.52	10	2.417	radiation, drilling, fracture filling
Garnet	cubic	3.40	5.5-6.5	1.700-1.746	none
Jadeite	microcystalline	3.34	6.5-7.0	1.660-1.680	dying
Opal	amorphous	2.15	5.0-6.5	1.450	fracture filling
Spinel	cubic	3.60	8	1.718	none