Science / Geology / Zoned Crystal: A crystal that grew while temperatures were changing or while the composition of the parent solution was changing. Crystals of these minerals can have a range of compositions, with a certain chemistry in the center reflecting the early growth conditions and the outer chemistry reflecting the later growth conditions. Minerals such as olivine or plagioclase which have a solid solution series frequently form such crystals.
Science / Geology / Recrystallization: A solid state reaction in which the atoms of existing crystals within a rock are reorganized in response to heat and/or pressure. The recrystallized mineral grains are typically larger in size than th MORE
Science / Chemistry / Perfect Crystal: A crystal with no defects or impurities, made of completely identical repeating subunits. Further, a perfect crystal has only one possible arrangement of subunits, with every subunit making exactly th MORE