A Grand Soul Gem is a medium-sized, crystalline object with a smooth, polished surface that captures and stores souls. It features a deep, vibrant purple hue with a faint, pulsating glow emanating from its core, indicating the presence of a trapped soul. The gem is cut into a multifaceted, symmetrical shape, with sharp, angular edges that refract light, creating an ethereal shimmer. Its surface is flawless, with no visible imperfections, and it feels cool to the touch, radiating a subtle magical energy.