Defect chemistry would be the review of position defects in imperfect crystals. These consist of vacancies, interstitial atoms or ions, trace components, electrons, or holes or some other deviation from the framework of an excellent crystal. Even Definitely pure crystals have stage defects at any temperature higher than complete zero. https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share