OCT refers to octagon cut synthetic spinel, a versatile shape with eight long facets. The broad planes produce substantial brilliance through multiple reflections. Each facet is carefully angled to balance light return. Sharp defined corners contrast beautifully with the wide table and open silhouette. OCT spinel sparkles brightly in tones like fuchsia and emerald. The symmetrical geometry creates a clean, modern look. Despite its straight edges, the OCT cut retains excellent durability.