Mystical Cosmic Crystal Illuminating Desert Night Sky

A majestic 4K wallpaper presenting a towering, multifaceted crystal glowing intensely in a serene desert at twilight, bordered by distant, silhouetted mountains. Its lower half radiates a brilliant golden light that illuminates the foreground's rippled sand, while its upper facets shimmer with a cool cosmic blue against the darkening, star-dusted sky.