The homogenization of silicate melt inclusions （SMIs）,small droplets of silicate melt trapped in magmatic minerals,is an important component of petrogenetic and magmatic research.Conventional homogenization experiments on SMIs use microscope-mounted heating stages capable of producing high temperatures at 1 atm and cold-seal high-pressure vessels.Heating stages are generally used for SMIs with low internal pressures and allow in situ observations of the homogenization processes.In contrast,cold-seal high-pressure vessels are generally used to heat SMIs that have high internal pressures,although the homogenized SMIs can only be observed after quenching in this approach.Here we outline an alternative approach that uses a hydrothermal diamond anvil cell （HDAC） apparatus to homogenize SMIs.This is the only current method wherein phase changes in high-internal-pressure SMIs can be observed in situ during homogenization experiments,which represents an advantage over other conventional methods.Using an HDAC apparatus prevents high-internal-pressure SMIs from decrepitating during heating by elevating their external pressure,in addition to allowing in situ observations of SMIs.The type-V HDAC that is currently being used has a shorter distance between the sample chamber and the observation window than earlier types,potentially enabling continuous observation of the processes involved in heating and SMI homogenization through an objective lens with a long working distance.Homogenization experiments using HDAC require that a number of steps,including HDAC preparation,sample preparation,sample loading,preheating,and formal heating,be carefully followed.Homogenization experiments on SMIs within granite samples from the Jiajika pegmatite deposit （Sichuan,China） are best performed using an HDAC-based approach,because the elevated proper external pressure of these SMIs,combined with a short heating duration,helps to suppress material leakage and any reactions within the SMIs,in addition to allowing in situ observatio
Objective Granitic pegmatite has great significance for studying magmatic-hydrothermal evolution, which is the main formation mechanism of rare metal deposits. Conventionally, granitic pegmatite rare metal deposits are regarded as crystallization from H20-saturated granite magma that formed in the late fractional crystallization of granitic magma. However, some scholars recently believed that the liquid immiscibility of granitic magma promoted the formation of pegmatite deposits. The Asikaerte beryllium deposit in Xinjiang, China, bearing metallogenic belts from lower granite belt to upper pegmatite belt, could benefit us to understand the formation of pegmatite through analyzing fluid and melt inclusions data.
