This article presents a novel, lightweight, full-polarized Luneburg lens (LL) antenna featuring a diamond lattice structure for the first time. While retaining the essential attributes of a full-scale LL, such as pencil-beam generation capability, high gain, wide bandwidth, and omnidirectional scanning, this LL leverages the isotropic nature of its diamond crystal structure to seamlessly adapt to various polarizations and a wide range of incident wave angles. Utilizing advanced three-dimensional-printing (3DP) technology, an intricately designed structure was fabricated. An elaborate wideband feeding system was also developed to serve as the primary feed for the lens. The proposed system supports typical polarization states and consists of a dual-polarized horn antenna integrated with a sextuple-polarized feeding network. The results indicate that the operation bandwidth of the proposed LL antenna covers the entire X-band (8-12 GHz) under any polarization scenario. Furthermore, the antenna exhibits consistent and stable gains, thereby simplifying the design complexity of signal processing systems. Compared with conventional LLs constructed with a cubic lattice structure, this innovative LL antenna boasts a reduced weight and diminished sidelobe levels. These advancements position the proposed design as a promising candidate for satellite communications, integrated sensing and communication, microwave imaging, and diverse future endeavors.