[Solved] The only sure way to identify a plagioclase feldspar from a potassium feldspar on large enough specimen to see with the naked eye is to____________ . A) find wormy exsolution lamellae going obliquely across the cleavages B) find multiple parallel twinning striations on a cleavage face C) compare their colours, plagioclase is always darker D) measure their exact cleavage angles, plagioclases have 120° Extinct Response: The diminishing or disappearance of a conditioned response when the reinforcement is no longer provided. Stimulus Generalization: The tendency for the conditioned response to be triggered by stimuli that are similar but not identical to the original conditioned stimulus. Conditioned Response: A learned response to a previously neutral stimulus that has been repeatedly presented along with an unconditioned stimulus. Conditioned Response: An automatic response established by training to an ordinarily neutral stimulus.