Table 2. Mineral Composition of Sandstone Samples from QEMSCAN Analysis (Clays Are Indicated in Bold Type).

	Kentucky		Bandera Brown		Berea
	1	2	1	2	1	2
mineral name	mass %	mass %	mass %	mass %	mass %	mass %
quartz	61.4	59.2	47.9	56.2	84.8	83.6
K-feldspar	0.9	0.7	0	0	2.7	3.2
plagioclase	15.2	14.5	10.3	11.1	1.5	1.7
siderite	0	0	0.1	0	0.5	0.6
mica	9.8	11.1	10.4	8.2	2.5	2.5
illite	5.4	9	7	6.7	2	2.5
smectite	0.5	0.3	0.3	0.3	0.1	0.1
kaolinite	0.3	0.4	2.9	3.8	2.6	3.8
chlorite	2.4	1.6	16.6	10.3	0.5	0.4
others	4.1	3.2	4.4	3.5	2.7	1.7
total clay	8.6	11.3	26.8	21.1	5.2	6.8