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Saurabh 1 Best Answer
This one you can find in any of the basic mineralogy book(by Dexter Perkins or by dana or by cornelis klein). Staurolite has characteristic cruciform twin (a type of penetration twin forming a cruciform pattern ✝️). So, P-> 4 Quartz shows characteristic Japan twin law with two crystals meeting at an angle of around 85°. So, Q-> 1 Gypsum shows characteristic Swallow tail twin in which the shape of twinned crystals resembles English alphabet V. So, R->2 Orthoclase shows characteristic Carlsbad twinning basically a type of penetration twinning. So, S-> 3. So correct option is D.