Abstract:Zircon is an accessory mineral in igneous rocks and can provide a record of hydrothermal alteration through variations in crystal structures, and geochemical properties. In samples of altered granitic pegmatite from the Baicaoduo region in the eastern part of East Qinling, three different forms of zircon were found. Type 1 zircons feature pronounced oscillatory zones, low trace element levels, and are concentrated in the heavy rare earth elements (HREE). Some Type 1 zircons also have a modest number of fractures near the rim. They are magmatic zircons because the Ce exhibits clear positive anomalies and significant negative Eu anomalies. Type 2 zircons have developed rim fractures and a core- mantle- rim structure. The core has similar CL and trace element characteristics to Type 1 zircon, which is magmatic zircon. Type 2 zircon mantle has dark spongy, uneven internal structure, occasionally contains zircon residue, a high trace element content, and inconspicuous Ce anomaly. It has hydrothermal zircon characteristics due to incomplete reworking of hydrothermal solution into zircon along the fracture. The Type 3 and Type 2 zircon mantles have comparable structural characteristics and trace element content, with abnormally high U and Th content and high Dα value, which is the result of complete hydrothermal reworking of Type 2 zircon. As a byproduct of later magmatic development known as granitic pegmatite, leftover magmatic hydrothermal enhances trace elements by crystallization differentiation. In granitic pegmatite, the zircon is reworked to varied degrees by the magmatic hydrothermal that penetrates the crystal via the zircon's fracture.