The　Lawu　Cu–Pb–Zn　deposit　is　situated　in　the　eastern　part　of　Nyainqêntanglha　metallogenic　belt,　Tibet.　It　represents　a　rare　indium　(In)-bearing　and　tin　(Sn)-poor　skarn　system,　however,　the　occurrence,　distribution,　and　endowment　of　In,　along　with　their　geochemical　controls,　remain　poorly　constrained.　In　this　contribution,　we　conducted　a　comprehensive　mineralogical　study　of　sulfides　using　microscopic　observation,　electron　probe　micro-analyzer　(EPMA),　and　laser　ablation　inductively　coupled　plasma　mass　spectrometer　(LA–ICP–MS).　Based　on　mineral　assemblage　and　textural　relationships,　four　types　of　sphalerite　are　identified:　sphalerite　I　as　micro-inclusions　within　chalcopyrite　and　pyrrhotite,　sphalerite　II　with　abundant　mineral　inclusions,　sphalerite　III　exhibiting　chalcopyrite　disease　with　watermelon　texture,　and　sphalerite　IV　displaying　a　relatively　clean　texture　with　minimal　inclusions.　Sphalerite　I　is　enriched　in　In,　Cu,　Cd,　and　Mn,　whereas　sphalerite　II　and　sphalerite　IV　exhibit　variable　contents　of　In,　Sn,　Cu,　Mn,　Co,　Se,　and　Ag.　Trace　elements,　such　as　In,　commonly　occur　in　sulfides　via　isomorphic　substitution,　with　minor　amounts　present　as　micron-scale　mineral　inclusions　(e.g.,　Cu　in　sphalerite;　Pb　and　Bi　in　sphalerite,　chalcopyrite,　and　pyrite).　From　the　perspective　of　In　content　in　minerals,　In　is　mainly　hosted　in　sphalerite　(average　＞400　ppm).　Chalcopyrite　also　shows　relatively　elevated　In　content　(average　∼200　ppm).　Pyrrhotite,　pyrite,　and　arsenopyrite　typically　contain　negligible　In　content,　generally　below　10　ppm.　According　to　the　GGIMFis　geothermometer　calculations,　the　crystallization　temperatures　of　sphalerite　II　to　sphalerite　IV　are　as　follows:　378　to　427　°C　(average　=　398　°C)　for　sphalerite　II,　389　to　399　°C　(395　°C)　for　sphalerite　III,　and　338　to　375　°C　(356　°C)　for　sphalerite　IV.　The　In,　Cu,　and　Co　contents　in　sphalerite　increase　with　crystallization　temperatures,　implying　that　their　incorporation　is　primarily　controlled　by　the　temperature　of　ore-forming　fluids.　Combined　with　the　published　sphalerite　dataset,　a　strong　correlation　is　inferred　between　In　and　Sn,　Cu,　or　Fe.　Notably,　Sn-poor　Zn-polymetallic　skarn　systems　represent　strategic　targets　for　In　resource　exploration.　This　finding　refines　the　understanding　of　In　occurrence　and　enrichment　in　Sn-poor　skarn　systems,　providing　insights　applicable　to　similar　geological　environments.　©　2025　Elsevier　Ltd