Aiming at a novel variety of serpentine jade named “Myanmar Lu Yu” with intermingled yellow-green and gray-white colors appearance in the Longling jewellery market of Yunnan, this study employed methods such as petrographic thin-section identification, X-ray powder diffraction, scanning electron microscopy and energy-dispersive spectroscopy, infrared spectroscopy, Raman spectroscopy, and Ultraviolet-visible spectroscopy to explore its mineral composition, chemical components, spectroscopic characteristics, the origin of its captivating color and to infer its ore-forming process. The results show that the jade exhibits fibrous and scaly metamorphic crystalline structures. The gray-white matrix is composed of brucite, while the yellow-green mineral is serpentine, with the serpentine crystals having better orientation than brucite. XRD result shows characteristic diffraction peaks of Antigorite at d₂₀₂=2.525 Å, d_-132=2.618 Å, and d₀₆₀=1.544 Å, and characteristic diffraction peaks at d₁₁₀=4.595 Å and d₀₆₁=1.499 Å of Lizardite. Insights obtained from SEM-EDS elucidate that the FeO_T content in the yellow-green part (5.11%) is much higher than in the gray-white matrix (0.52%). It is speculated that Fe exists in two ways: one is that Fe²⁺ isomorphic substitutes for Mg²⁺ to form ferric Brucite, which is very minor; the other is that Fe²⁺ and Fe³⁺ isomorphic substitutes for Mg²⁺ and Si⁴⁺ enter the crystal structure of serpentine to form ferric serpentine, which constitutes the majority. In addition, there are small amounts of sphalerite, zinc oxide, and trace amounts of metal impurities such as Fe, Co, Ni, Mn, and Cu. Based on the chemical composition and UV-Vis spectroscopic characteristics, it is concluded that the iron element colors the jade. The strong and broad absorption band at 653 nm in the UV-Vis spectrum is caused by Fe²⁺→Fe³⁺ charge transfer, resulting in green color. The moderate absorptions at 435 and 457 nm are due to the spin-forbidden transitions ⁶A₁(⁶S)→${}_{\text{a}}^4{\text{T}}_1\left(4\text{G}\right)$ and ⁶A₁→⁴E₁+⁴A₁(⁴G) of Fe³⁺, resulting in a yellow color. The superposition of these two absorption effects gives the jade its yellow-green appearance. This jade's uniqueness compared to other serpentine jade varieties lies in the absence of obvious mineral indicators of its genesis. Based on its mineral composition, structure, and color characteristics, it is inferred that this serpentine jade is of ultramafic rock hydrothermal autometasomatic origin, with the formation process divided into three stages: (1) cooling and crystallization differentiation of magnesium-rich ultrabasic magma to form olivineduring its ascent and migration from the mantle; (2) hydrothermal alteration of olivine to serpentine completely during the late stage of magmatic lithogenesis, which is the autometasomatic process of ultrabasic rocks; (3) infiltration of strongly alkaline hot water solutions into fractures after the magmatic period, promoting partial hydrolysis of serpentine to form brucite, which fills the structural fractures in vein-like and patch-like patterns. Serpentine is a product of hydrothermal alteration of ultrabasic magmatic rocks, while brucite is a secondary product formed after the magmatic phase.