3D Model: Create A 3D Model Of The Mathematical Sigma Symbol (∑) With A Crystal Glass Appearance. The Symbol Should Have Sharp, Geometric Edges Like Cut Crystal, With High Reflectivity And Transparency. Add Prismatic Light Refraction Effects And Make It Extremely Glossy And Shiny. The Surface Should Have Faceted Crystal Cuts That Catch And Reflect Light Beautifully. Use Clear Crystal Material With Rainbow Light Dispersion, Similar To High-quality Cut Diamond Or Crystal Glass. Make The Symbol Thick And Substantial With Clean, Precise Mathematical Proportions.