Growth Sector is defined as which option?

• A. A linear region of crystal growth
• B. A three-dimensional region with a common crystallographic growth plane
• C. A surface defect in crystal lattice
• D. A zone of impurity concentration

Answer: (B)

Growth sectors are portions of a crystal that grow from the same crystallographic plane, forming a distinct three-dimensional region bounded by that plane orientation. In crystal growth, different planes advance at different rates, so when a sector starts on a particular plane, all of its volume shares that same plane orientation, producing a cohesive block within the crystal. In diamonds, you can often see these sectors as segmented blocks on the crystal, with boundaries that follow specific crystallographic planes. These boundaries arise because growth proceeds along a single plane, which is why a sector is a 3D region defined by a common growth plane. The other descriptions don’t capture that idea: a linear region is just a line of growth, a surface defect is a lattice imperfection, and a zone of impurity concentration relates to chemical distribution rather than a crystallographic growth plane.