| Tacharanite | Ca₁₂Al₂Si₁₈O₃₃(OH)₃₆ | Monoclinic | — | — |
| Tachyhydrite | CaMg₂Cl₆·12H₂O | Trigonal | 2.0 | — |
| Tadzhikite-(Ce) | Ca₄Ce³⁺₂Ti☐(B₄Si₄O₂₂)(OH)₂ | — | — | — |
| Taenite | (Ni,Fe) | Cubic | — | — |
| Taikanite | Sr₃BaMn²⁺₂(Si₄O₁₂)O₂ | — | — | — |
| Taimyrite | (Pd,Pt)₉Cu₃Sn₄ | Orthorhombic | — | — |
| Tainiolite | KLiMg₂Si₄O₁₀F₂ | Monoclinic | — | — |
| Taipingite-(CeCa) | (Ce₇Ca₂)Mg(SiO₄)₃[SiO₃(OH)]₄F₃ | Trigonal | — | — |
| Takanawaite-(Y) | YTaO₄ | Monoclinic | — | 7.52 g/cm³ |
| Takanelite | (Mn²⁺,Ca)₂ₓ(Mn⁴⁺)₁₋ₓO₂·0.7H₂O | — | — | — |
| Takedaite | — | Trigonal | — | — |
| Takovite | Ni₆Al₂(OH)₁₆[CO₃]·4H₂O | Trigonal | — | — |
| Takéuchiite | Mg₂Mn³⁺O₂(BO₃) | Orthorhombic | — | — |
| Talc | — | Hexagonal | 1.0 | 2.75 g/cm³ |
| Talmessite | Ca₂Mg(AsO₄)₂·2H₂O | — | 5.0 | — |
| Talnakhite | Cu₉Fe₈S₁₆ | Cubic | — | 4.29 g/cm³ |
| Tamaite | (Ca,K,Ba,Na)₃-₄Mn₂₄(Si,Al)₄₀(O,OH)₁₁₂·nH₂O | Monoclinic | — | — |
| Tamarugite | NaAl(SO₄)₂·6H₂O | Monoclinic | — | — |
| Tamboite | Fe³⁺₃(OH)(H₂O)₂(SO₄)(Te₄+O₃)₃(Te₄+O(OH)₂)(H₂O)₃ | Monoclinic | — | — |
| Tancaite-(Ce) | FeCe(MoO₄)₃·3H₂O | Trigonal | — | — |
| Tancoite | LiNa₂Al(PO₄)(HPO₄)(OH) | Orthorhombic | — | — |
| Taneyamalite | (Na,Ca)(Mn,Mg,Fe)₁₂Si₁₂(O,OH)₄₄ | — | — | — |
| Tangdanite | Ca₂Cu₉(AsO₄)₄(SO₄)₀.₅(OH)₉·9H₂O | Monoclinic | — | — |
| Tangeite | CaCu(VO₄)(OH) | — | 3.5 | — |
| Taniajacoite | SrCaMn³⁺₂Si₄O₁₁(OH)₄·2H₂O | Triclinic | — | — |
| Tanohataite | LiMn₂Si₃O₈(OH) | Triclinic | — | — |
| Tantalaeschynite-(Ce) | Ce(TiTa)O₆ | Orthorhombic | — | — |
| Tantalaeschynite-(Y) | Ce(TiTa)O₆ | Orthorhombic | — | — |
| Tantalcarbide | TaC | Cubic | — | 14.37 g/cm³ |
| Tantalite-(Fe) | Fe²⁺Ta₂O₆ | Orthorhombic | — | — |
| Tantalite-(Mg) | MgTa₂O₆ | Orthorhombic | — | 7.79 g/cm³ |
| Tantalite-(Mn) | Mn²⁺Ta₂O₆ | Orthorhombic | — | — |
| Tantalowodginite | (Mn☐)TaTa₂O₈ | — | — | — |
| Tanteuxenite-(Y) | Y(Ta,Nb,Ti)₂(O,OH)₆ | — | — | — |
| Tantite | Ta₂O₅ | Triclinic | — | — |
| Tapiaite | Ca₅Al₂(AsO₄)₄(OH)₄·12H₂O | Monoclinic | — | — |
| Tapiolite-(Fe) | (Fe,Mn)(Ta,Nb)₂O₆ | Tetragonal | — | — |
| Tapiolite-(Mn) | Mn²⁺Ta₂O₆ | Tetragonal | — | — |
| Taramellite | Ba₄(Fe³⁺,Ti,Fe²⁺,Mg)₄(B₂Si₈O₂₇)O₂Clx | — | — | — |
| Taramite | NaCaNa(Mg₃Al₂)Al₂Si₆O₂₂(OH)₂ | Monoclinic | — | — |
| Taranakite | K₃Al₅(PO₃OH)₆(PO₄)₂·18H₂O | Trigonal | — | — |
| Tarapacáite | K₂CrO₄ | Orthorhombic | — | — |
| Tarbagataite | (K☐)Ca(Fe,Mn)₇Ti₂(Si₄O₁₂)₂O₂(OH)₅ | Triclinic | — | — |
| Tarbuttite | Zn₂(PO₄)(OH) | Triclinic | — | — |
| Tarkianite | (Cu,Fe)(Re,Mo)₄S₈ | Cubic | — | — |
| Tartarosite | C | Cubic | — | — |
| Tarutinoite | Ag₃Pb₇Bi₇S₁₉ | Monoclinic | — | — |
| Taseqite | Na₁₂Sr₃Ca₆Fe₃Zr₃Nb[(Si₃O₉)₂(Si₉O₂₇)₂SiO]Cl₂(O,OH,H₂O)₃ | Trigonal | — | — |
| Tashelgite | CaMgFe²⁺Al₉O₁₆(OH) | Monoclinic | — | — |
| Tassieite | NaCa₂Mg₃Fe²⁺₂F³⁺(PO₄)₆·2H₂O | — | — | — |
| Tatarinovite | Ca₃Al(SO₄)[B(OH)₄](OH)₆·12H₂O | Hexagonal | — | — |
| Tatarskite | Ca₆Mg₂(SO₄)₂(CO₃)₂(OH)₄Cl₄·7H₂O | Orthorhombic | — | — |
| Tatyanaite | (Pt,Pd,Cu)₉Cu₃Sn₄ | Orthorhombic | — | — |
| Tausonite | SrTiO₃ | Cubic | — | — |
| Tavagnascoite | Bi₄O₄(SO₄)(OH)₂ | Orthorhombic | — | — |
| Tavorite | LiFe³⁺(PO₄)(OH) | — | — | — |
| Tazheranite | (Zr,Ti,Ca)(O,☐)₂ | — | — | — |
| Tazieffite | Pb₂₀Cd₂(As,Bi)₂₂S₅₀Cl₁₀ | Monoclinic | — | — |
| Tazzoliite | Ba₂CaSr₀.₅Na₀.₅Ti₂Nb₃SiO₁₇[PO₂(OH)₂]₀.₅ | Orthorhombic | — | — |
| Teallite | PbSnS₂ | Orthorhombic | 1.5 | — |
| Tedhadleyite | Hg²⁺Hg⁺₁₀O₄I₂(Cl,Br)₂ | Triclinic | — | — |
| Teepleite | Na₂[B(OH)₄]Cl | Tetragonal | — | — |
| Tegengrenite | (Mn³⁺₀.₅Sb⁵⁺₀.₅)Mg₂O₄ | Trigonal | — | — |
| Teineite | Cu²⁺Te⁴⁺O₃·2H₂O | — | — | — |
| Telargpalite | (Pd,Ag)₃(Te,Bi) | Cubic | — | — |
| Tellurantimony | Sb₂Te₃ | Trigonal | — | 6.12 g/cm³ |
| Telluric iron | Fe | Cubic | — | — |
| Tellurite | TeO₂ | Tetragonal | 2.0 | — |
| Tellurium | Te | Trigonal | — | — |
| Tellurobismuthite | Bi₂Te₃ | Trigonal | — | 7.32 g/cm³ |
| Tellurohauchecornite | Ni₉BiTeS₈ | Tetragonal | — | — |
| Telluromandarinoite | Fe³⁺₂(Te⁴⁺O₃)₃·6H₂O | Monoclinic | — | — |
| Telluronevskite | Bi₃TeSe₂ | Trigonal | — | — |
| Telluropalladinite | Pd₉Te₄ | Monoclinic | — | 10.27 g/cm³ |
| Telluroperite | Pb₃Te⁴⁺O₄Cl₂ | Orthorhombic | — | — |
| Telyushenkoite | (Cs,Na,K)Na₆[Be₂Al₃Si₁₅O₃₉]F₂ | Trigonal | — | — |
| Temagamite | Pd₃HgTe₃ | Orthorhombic | — | — |
| Tengchongite | CaO(UO₂)₆(MoO₄)₂O₅·12H₂O | Orthorhombic | — | — |
| Tengerite-(Y) | Y₂(CO₃)₃·2-3H₂O | Orthorhombic | — | — |
| Tennantite-(Fe) | Cu₁₀Fe₂As₄S₁₃ | Cubic | — | — |
| Tennantite-(Hg) | — | Cubic | — | — |
| Tennantite-(In) | Cu₆(Cu₅In)As₄S₁₃ | Cubic | — | — |
| Tennantite-(Ni) | — | Cubic | — | — |
| Tenorite | CuO | Monoclinic | 3.5 | 6.30 g/cm³ |
| Tephroite | Mn²⁺₂SiO₄ | Orthorhombic | 6.0 | — |
| Terlinguacreekite | Hg²⁺₃Cl₂O₂ | Orthorhombic | — | — |
| Terlinguaite | Hg₂OCl | Monoclinic | — | — |
| Ternesite | Ca₅(SiO₄)₂(SO₄) | Orthorhombic | — | — |
| Ternovite | MgNb₄O₁₁·8-12H₂O | Monoclinic | — | — |
| Terranovaite | (Na,Ca)₈(Si₆₈Al₁₂)O₁₆₀·~8H₂O | Orthorhombic | — | — |
| Terrywallaceite | AgPb(Sb,Bi)₃S₆ | Monoclinic | — | — |
| Terskite | Na₄ZrSi₆O₁₆·2H₂O | — | — | — |
| Tertschite | Ca₄B₁₀O₁₉·20H₂O | — | — | — |
| Teruggite | Ca₄Mg[AsB₆O₁₁(OH)₆]₂(H₂O)₁₂·2H₂O | Monoclinic | 2.5 | — |
| Teschemacherite | (NH₄)HCO₃ | Orthorhombic | 1.5 | 1.61 g/cm³ |
| Testibiopalladite | PdSbTe | Cubic | — | — |
| Tetra-auricupride | CuAu | Tetragonal | — | 14.86 g/cm³ |
| Tetradymite | Bi₂Te₂S | Trigonal | — | 7.09 g/cm³ |
| Tetraferriannite | KFe²⁺₃((Fe³⁺,Al)Si₃O₁₀)(OH)₂ | — | — | — |
| Tetraferriphlogopite | KMg₃(Fe³⁺Si₃O₁₀)(OH,F)₂ | — | — | — |
| Tetraferroplatinum | PtFe | Tetragonal | — | 14.98 g/cm³ |
| Tetrahedrite-(Cd) | Cu₆(Cu₄Cd₂)Sb₄S₁₂S | Cubic | — | — |
| Tetrahedrite-(Cu) | Cu₆(Cu₄Cu²⁺₂)Sb₄S₁₂S | — | — | — |
| Tetrahedrite-(Hg) | — | Cubic | — | — |
| Tetrahedrite-(Mn) | — | Cubic | — | — |
| Tetrahedrite-(Ni) | — | Cubic | — | — |
| Tetrarooseveltite | Bi(AsO₄) | Tetragonal | — | 7.62 g/cm³ |
| Tetrataenite | FeNi | Monoclinic | — | 8.54 g/cm³ |
| Tetrawickmanite | Mn²⁺Sn⁴⁺(OH)₆ | — | — | — |
| Tewite | K₂(Te₁.₅☐₀.₅)₂W₅O₁₉ | Orthorhombic | — | — |
| Thadeuite | CaMg₃(PO₄)₂(OH,F)₂ | Orthorhombic | — | — |
| Thalcusite | Tl₂Cu₃FeS₄ | Tetragonal | — | — |
| Thalfenisite | Tl₆(Fe,Ni,Cu)₂₅S₂₆Cl | Cubic | — | — |
| Thalhammerite | Pd₉Ag₂Bi₂S₄ | Tetragonal | — | — |
| Thalliomelane | — | Tetragonal | — | — |
| Thalliumpharmacosiderite | TlFe₄[(AsO₄)₃(OH)₄]·4H₂O | Cubic | — | — |
| Thalénite-(Y) | Y₃Si₃O₁₀F | Monoclinic | — | — |
| Thaumasite | Ca₃Si(OH)₆(SO₄)(CO₃)·12H₂O | Hexagonal | 3.5 | — |
| Thebaite-(NH4) | — | Monoclinic | — | — |
| Theisite | Cu₅Zn₅(AsO₄,SbO₄)₂(OH)₁₄ | — | — | — |
| Theoparacelsite | Cu₃(As₂O₇)(OH)₂ | Orthorhombic | — | — |
| Theophrastite | Ni(OH)₂ | Trigonal | — | — |
| Therasiaite | (NH₄)₃KNa₂Fe²⁺Fe³⁺(SO₄)₃Cl₅ | Monoclinic | — | — |
| Thermaerogenite | CuAl₂O₄ | Cubic | 7.0 | — |
| Thermessaite | K₂AlF₃(SO₄) | Orthorhombic | — | 2.80 g/cm³ |
| Thermessaite-(NH4) | (NH₄)₂AlF₃(SO₄) | Orthorhombic | — | — |
| Thermonatrite | Na₂CO₃·H₂O | Orthorhombic | — | — |
| Theuerdankite | Ag₃AsO₄ | Cubic | 2.0 | — |
| Thionasilite | Na₂Si₂S₂O₃ | Orthorhombic | — | — |
| Thomasclarkite-(Y) | (Na,Ce)(Y,REE)(HCO₃)(OH)₃·4H₂O | Monoclinic | — | — |
| Thometzekite | PbCu²⁺₂(AsO₄)₂·2H₂O | — | — | — |
| Thomsenolite | NaCaAlF₆·H₂O | Monoclinic | 2.0 | — |
| Thomsonite-Ca | NaCa₂(Al₅Si₅)O₂₀·6H₂O | Orthorhombic | — | — |
| Thomsonite-Sr | NaSr₂Al₅Si₅O₂₀·(6-7)H₂O | Orthorhombic | — | — |
| Thorasphite | Th₂H(PO₄,AsO₄)₃·6H₂O | — | — | — |
| Thorbastnäsite | ThCa(CO₃)₂F₂·3H₂O | Hexagonal | — | — |
| Thoreaulite | (Sn²⁺,Pb)(Ta,Nb)₂O₆ | — | — | — |
| Thorianite | ThO₂ | Cubic | — | 9.98 g/cm³ |
| Thorikosite | Pb₃Cl₂(OH)(SbO₃,AsO₃) | — | — | — |
| Thorite | ThSiO₄ | Tetragonal | — | 6.66 g/cm³ |
| Thornasite | Na₁₂Th₃(Si₈O₁₉)₄·(H₂O)₁₂·6H₂O | — | — | — |
| Thorneite | Pb₆(Te₂O₁₀)(CO₃)Cl₂(H₂O) | Monoclinic | — | — |
| Thorosteenstrupine | (Ca,Th,Mn)₃Si₄O₁₁F·6H₂O | Amorphous | — | — |
| Thortveitite | Sc₂Si₂O₇ | Monoclinic | — | 3.37 g/cm³ |
| Thorutite | (Th,U,Ca)Ti₂(O,OH)₆ | — | — | — |
| Threadgoldite | Al(UO₂)₂(PO₄)₂(OH)·8H₂O | — | — | — |
| Thunderbayite | TlAg₃Au₃Sb₇S₆ | Triclinic | 3.0 | 5.69 g/cm³ |
| Thénardite | Na₂SO₄ | Orthorhombic | — | 2.74 g/cm³ |
| Thérèsemagnanite | — | Hexagonal | — | — |
| Tianhuixinite | (MoO₃)₃·H₂O | — | — | — |
| Tiberiobardiite | {Cu₉Al[SiO₃(OH)]₂(OH)₁₂(H₂O)₆}(SO₄)₁.₅·10H₂O | Trigonal | — | — |
| Tiemannite | HgSe | Cubic | — | 8.31 g/cm³ |
| Tienshanite | KNa₃Na₆Ca₂Ba₆Mn₆(Ti₄+,Nb)₆B₁₂Si₃₆O₁₁₄(O,OH,F)₁₁ | Hexagonal | — | — |
| Tiettaite | (Na,K)₁₇FeTiSi₁₆O₂₉(OH)₃₀·2H₂O | Orthorhombic | — | — |
| Tikhonenkovite | SrAlF₄(OH)(H₂O)₂ | Monoclinic | — | — |
| Tilasite | CaMg(AsO₄)F | Monoclinic | — | 3.63 g/cm³ |
| Tilkerodeite | — | Trigonal | 3.0 | 9.67 g/cm³ |
| Tilleyite | Ca₅Si₂O₇(CO₃)₂ | Monoclinic | — | — |
| Tillmannsite | (Ag₃Hg)(VO₄,AsO₄) | Tetragonal | — | — |
| Timroseite | Pb₂Cu₅(TeO₆)₂(OH)₂ | Orthorhombic | — | — |
| Tin (native) | Sn | Tetragonal | — | — |
| Tinaksite | K₂Na(Ca,Mn²⁺)₂Ti[O|Si₇O₁₈(OH)] | — | — | — |
| Tincalconite | Na₂B₄O₅(OH)₄·3H₂O | Trigonal | — | — |
| Tinnunculite | C₅H₄N₄O₃·2H₂O | Monoclinic | — | — |
| Tinsleyite | KAl₂(PO₄)₂(OH)(H₂O)₂ | Monoclinic | — | — |
| Tinticite | Fe³⁺₅.₃₄(PO₄)₃.₆₂(VO₄)₀.₃₈(OH)₄·3H₂O | Triclinic | — | — |
| Tintinaite | Pb₁₀Cu₂Sb₁₆S₃₅ | Orthorhombic | — | — |
| Tinzenite | Ca₆Al₄[B₂Si₈O₃₀](OH)₂ | Triclinic | — | — |
| Tiptopite | K₂(Li,Na,Ca)₆(Be₆P₆)O₂₄(OH)₂·1.3H₂O | Hexagonal | 3.5 | — |
| Tiragalloite | Mn²⁺₄As₅+Si₃O₁₂(OH) | Monoclinic | — | — |
| Tischendorfite | Pd₈Hg₃Se₉ | Orthorhombic | — | 8.87 g/cm³ |
| Tisinalite | Na₃H₃(Mn,Ca,Fe)TiSi₆(O,OH)₁₈ * 2H₂O | Trigonal | — | — |
| Tissintite | (Ca,Na,☐)AlSi₂O₆ | Monoclinic | — | — |
| Tistarite | Ti₂O₃ | Trigonal | — | — |
| Titanite | CaTiSiO₅ | Monoclinic | 5.5 | 3.42 g/cm³ |
| Titanium (native) | Ti | Hexagonal | — | — |
| Titanoholtite | (Ti₀.₇₅☐₀.₂₅)Al₆BSi₃O₁₈ | Orthorhombic | — | — |
| Titanomaghemite | Fe(Fe,Ti)₂O₄ | Cubic | — | — |
| Titanowodginite | Mn²⁺TiTa₂O₈ | — | — | — |
| Titantaramellite | Ba₄(Ti,Fe³⁺,Fe²⁺,Mg)₄(B₂Si₈O₂₇)O₂Clx | — | — | — |
| Tivanite | V³⁺TiO₃(OH) | — | — | — |
| Tlalocite | Cu₁₀Zn₆(Te₆+O₄)₂(Te₄+O₃)(OH)₂₅Cl·27H₂O | Orthorhombic | 1.0 | — |
| Tlapallite | (Ca,Pb)₃CaCu₆[Te₄+₃Te₆+O₁₂]₂(Te₄+O₃)₂(SO₄)₂·3H₂O | Monoclinic | — | — |
| Tobelite | (NH₄,K)Al₂(AlSi₃O₁₀)(OH)₂ | — | — | — |
| Tobermorite | Ca₄Si₆O₁₇(H₂O)₂·(Ca·3H₂O | Orthorhombic | — | — |
| Tochilinite | Fe²⁺₅-₆(Mg,Fe²⁺)₅S₆(OH)₁₀ | — | — | — |
| Tocornalite | (Ag,Hg)I (?) | — | — | — |
| Todorokite | (Na,Ca,K,Ba,Sr)₁-x(Mn,Mg,Al)₆O₁₂·3-4H₂O | Monoclinic | — | — |
| Tokkoite | K₂Ca₄[Si₇O₁₈(OH)](OH,F) | — | — | — |
| Tokyoite | Ba₂Mn³⁺(VO₄)₂(OH) | Monoclinic | — | — |
| Tolbachite | CuCl₂ | Monoclinic | — | 3.26 g/cm³ |
| Toledoite | TiFeSi | Orthorhombic | — | 5.62 g/cm³ |
| Tolovkite | IrSbS | Cubic | — | 10.26 g/cm³ |
| Tomamaeite | Cu₃Pt | Cubic | — | 12.82 g/cm³ |
| Tombstoneite | — | Trigonal | — | — |
| Tomcampbellite | [KCl][Fe²⁺₁₄(OH)₆(PO₄)₆(PO₃OH)₂] | Monoclinic | — | — |
| Tomichite | V³⁺₄Ti⁴⁺₃As³⁺O₁₃(OH) | — | — | — |
| Tomiolloite | — | Hexagonal | — | — |
| Tondiite | Cu₃MgCl₂(OH)₆ | Trigonal | — | — |
| Tongbaite | Cr₃C₂ | Orthorhombic | 8.5 | 6.92 g/cm³ |
| Tongxinite | — | Cubic | 3.5 | 7.38 g/cm³ |
| Tooeleite | Fe³⁺₆(As³⁺O₃)₄(SO₄)(OH)₄·4H₂O | — | 3.0 | — |
| Topaz | Al₂SiO₄F₂ | Orthorhombic | 8.0 | 3.53 g/cm³ |
| Topsøeite | — | Tetragonal | — | — |
| Torbernite | Cu(UO₂)₂(PO₄)₂·12H₂O | Tetragonal | — | — |
| Torrecillasite | Na(As,Sb)³⁺₄O₆Cl | Orthorhombic | — | — |
| Torreyite | — | Monoclinic | — | — |
| Torryweiserite | — | Trigonal | — | — |
| Tosudite | Na₀.₅(Al,Mg)₆((Si,Al)₈O₁₈)(OH)₁₂·5H₂O | — | — | — |
| Toturite | Ca₃Sn₂(SiFe³⁺₂)O₁₂ | Cubic | — | — |
| Tounkite | (Na,Ca,K)₈(Al₆Si₆O₂₄)(SO₄)₂Cl·0.5H₂O | Hexagonal | — | — |
| Touretite | LiAl₄Be₄(B₁₁Be)O₂₈ | Cubic | — | — |
| Townendite | Na₈ZrSi₆O₁₈ | Trigonal | — | — |
| Toyohaite | Ag₂FeSn₃S₈ | Cubic | 4.0 | 4.94 g/cm³ |
| Trabzonite | Ca₄(Si₃O₉)(OH)₂ | Monoclinic | — | — |
| Tranquillityite | (Fe²⁺,Ca)₈(Zr,Y)₂Ti₃(SiO₄)₃O₁₂ | Hexagonal | — | — |
| Transjordanite | Ni₂P | Hexagonal | — | — |
| Traskite | Ba₂₁Ca(Fe²⁺,Mn,Ti)₄(Ti,Fe,Mg)₁₂(Si₁₂O₃₆)(Si₂O₇)₆(O,OH)₃₀Cl₆·14H₂O | Hexagonal | — | — |
| Trattnerite | ☐(Fe³⁺,Mg,Fe²⁺)₂(Mg,Fe²⁺,Fe³⁺)₃(Si₁₂O₃₀) | — | — | — |
| Treasurite | Ag₇Pb₆Bi₁₅S₃₀ | Monoclinic | — | — |
| Trebiskyite | Na₃Mg₂[TiV₉O₂₈]·22H₂O | Monoclinic | — | — |
| Trechmannite | AgAsS₂ | — | — | — |
| Tredouxite | NiSb₂O₆ | Tetragonal | — | 6.61 g/cm³ |
| Trembathite | (Mg,Fe)₃(B₇O₁₃)Cl | Trigonal | — | — |
| Tremolite | ☐Ca₂Mg₅Si₈O₂₂(OH)₂ | Monoclinic | — | — |
| Trevorite | NiFe³⁺₂O₄ | Cubic | — | — |
| Triangulite | Al₃(UO₂)₄(PO₄)₄(OH)₅·5H₂O | — | — | — |
| Triazolite | NaCu₂(N₃C₂H₂)₂(NH₃)₂Cl₃·4H₂O | Orthorhombic | — | — |
| Tridymite | SiO₂ | Orthorhombic | 7.0 | 2.63 g/cm³ |
| Trigodomeykite | Cu₃As | — | — | — |
| Trigonite | Pb₃Mn²⁺(As³⁺O₃)₂(As³⁺O₂OH) | — | — | — |
| Trikalsilite | K₂NaAl₃(SiO₄)₃ | Hexagonal | — | — |
| Trilithionite | K(Li₁.₅Al₁.₅)(AlSi₃O₁₀)(F,OH)₂ | — | — | — |
| Trimerite | CaBe₃Mn²⁺₂(SiO₄)₃ | Monoclinic | — | — |
| Trimounsite-(Y) | Y₂Ti₂(SiO₄)O₅ | Monoclinic | — | — |
| Trinepheline | NaAlSiO₄ | Hexagonal | — | 2.58 g/cm³ |
| Triphylite | LiFe²⁺PO₄ | Orthorhombic | — | — |
| Triplite | Mn²⁺₂PO₄F | Monoclinic | — | — |
| Triploidite | (Mn²⁺,Fe²⁺)₂(PO₄)(OH) | — | — | — |
| Trippkeite | Cu²⁺As³⁺₂O₄ | Tetragonal | — | — |
| Tripuhyite | Fe³⁺Sb⁵⁺O₄ | — | — | — |
| Tristramite | (Ca,U,Fe)(PO₄,SO₄)·2H₂O | Hexagonal | — | — |
| Tritomite-(Ce) | Ce₅(SiO₄,BO₄)₃(OH,O) | — | — | — |
| Tritomite-(Y) | Y₅(SiO₄,BO₄)₃(O,OH,F) | — | — | — |
| Trogtalite | CoSe₂ | Cubic | 7.0 | 6.90 g/cm³ |
| Troilite | FeS | Hexagonal | — | 4.29 g/cm³ |
| Trolleite | Al₄(PO₄)₃(OH)₃ | Monoclinic | — | — |
| Trona | Na₃(HCO₃)(CO₃)·2H₂O | Monoclinic | — | — |
| Truscottite | (Ca,Mn)₁₄Si₂₄O₅₈(OH)₈·2H₂O | — | — | — |
| Trébeurdenite | Fe²⁺₂Fe³⁺₄O₂(OH)₁₀(CO₃)·3H₂O | Trigonal | — | — |
| Trögerite | (H₃O)(UO₂)(AsO₄)·3H₂O | Tetragonal | — | — |
| Trüstedtite | Ni₃Se₄ | Cubic | — | — |
| Tsangpoite | Ca₅(PO₄)₂(SiO₄) | Hexagonal | — | — |
| Tsaregorodtsevite | (N(CH₃)₄)(AlSi₅O₁₂) | Orthorhombic | — | — |
| Tschaunerite | (Fe²⁺)(Fe²⁺Ti₄+)O₄ | Orthorhombic | — | — |
| Tschermakite | ☐Ca₂(Mg₃Al₂)Si₆Al₂O₂₂(OH)₂ | Monoclinic | 5.5 | — |
| Tschermigite | NH₄Al(SO₄)₂·12H₂O | Cubic | 1.5 | — |
| Tschernichite | CaAl₂Si₆O₁₆·8H₂O | Tetragonal | — | — |
| Tschörtnerite | Ca₄(K,Ca,Sr,Ba)₃Cu₃Al₁₂Si₁₂O₄₈(OH)₈·20H₂O | Cubic | — | — |
| Tsepinite-Ca | (Ca,K,Na)₂₋ₓ(Ti,Nb)₂(Si₄O₁₂)(OH,O)₂·4H₂O | — | — | — |
| Tsepinite-K | (K,Ba,Na)₂(Ti,Nb)₂(Si₄O₁₂)(OH,O)₂·3H₂O | — | — | — |
| Tsepinite-Na | (Na,H₃O,K,Sr,Ba,☐)₂(Ti,Nb)₂(Si₄O₁₂)(OH,O)₂·3H₂O | — | — | — |
| Tsepinite-Sr | (Sr,Ba,K)(Ti,Nb)₂(Si₄O₁₂)(OH,O)₂·3H₂O | Monoclinic | — | — |
| Tsikourasite | Mo₃Ni₂P₁₊ₓ | Cubic | — | — |
| Tsilaisite | NaMn²⁺₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH) | Trigonal | 7.0 | — |
| Tsnigriite | Ag₉SbTe₃S₃ | — | — | — |
| Tsugaruite | Pb₄As₂S₇ | — | — | — |
| Tsumcorite | PbZn₂(AsO₄)₂·2H₂O | Monoclinic | 4.5 | — |
| Tsumebite | Pb₂Cu(PO₄)(SO₄)(OH) | — | 3.5 | — |
| Tsumgallite | GaO(OH) | Orthorhombic | — | 5.20 g/cm³ |
| Tsumoite | BiTe | Trigonal | — | — |
| Tsygankoite | Mn₈Tl₈Hg₂(Sb₂₁Pb₂Tl)S₄₈ | — | — | — |
| Tubulite | Ag₂Pb₂₂Sb₂₀S₅₃ | Monoclinic | — | — |
| Tugarinovite | MoO₂ | — | — | — |
| Tugtupite | Na₄BeAlSi₄O₁₂Cl | Tetragonal | 4.0 | 2.46 g/cm³ |
| Tuhualite | NaFe²⁺Fe³⁺Si₆O₁₅ | — | — | — |
| Tuite | Ca₃(PO₄)₂ | Trigonal | — | 2.78 g/cm³ |
| Tulameenite | CuFePt₂ | Tetragonal | — | — |
| Tuliokite | Na₆BaTh(CO₃)₆·6H₂O | Trigonal | — | — |
| Tululite | Ca₁₄(Fe³⁺,Al)(Al,Zn,Fe³⁺,Si,P,Mn,Mg)₁₅O₃₆ | Cubic | — | — |
| Tumchaite | Na₂Zr(Si₄O₁₁)·2H₂O | Monoclinic | — | — |
| Tundrite-(Ce) | Na₂Ce₂TiO₂(SiO₄)(CO₃)₂ | Triclinic | 3.0 | — |
| Tundrite-(Nd) | Na₂Nd₂TiO₂(SiO₄)(CO₃)₂ | — | — | — |
| Tunellite | SrB₆O₉(OH)₂·3H₂O | Monoclinic | — | — |
| Tungsten (native) | W | Cubic | — | 19.27 g/cm³ |
| Tungstenite | WS₂ | Hexagonal | — | 7.23 g/cm³ |
| Tungstibite | Sb₂WO₆ | Orthorhombic | — | — |
| Tungstite | WO₃·H₂O | — | — | — |
| Tungusite | Ca₄Fe₂Si₆O₁₅(OH)₆ | — | — | — |
| Tunisite | NaCa₂Al₄(CO₃)₄(OH)₈Cl | Tetragonal | — | — |
| Tuperssuatsiaite | Na₂Fe₃Si₈O₂₀(OH)₂·4H₂O | Monoclinic | — | — |
| Turanite | Cu₅(VO₄)₂(OH)₄ | Triclinic | — | — |
| Turkestanite | (K,☐)(Ca,Na)₂ThSi₈O₂₀·nH₂O | Tetragonal | — | — |
| Turneaureite | Ca₅(AsO₄)₃Cl | Hexagonal | — | — |
| Turquoise | CuAl₆(PO₄)₄(OH)₈·4H₂O | Triclinic | — | — |
| Turtmannite | (Mn,Mg)₂₂.₅Mg₃-₃x((V₅+,As₅+)O₄)₃(As³⁺O₃)x(SiO₄)₃O₅-₅x(OH)₂₀+x | — | — | — |
| Tuscanite | (K(Ca,Na)₆(Si,Al)₁₀O₂₂[SO₄,CO₃,(OH)₂])·H₂O | — | — | — |
| Tusionite | Mn²⁺Sn₄+[BO₃]₂ | Trigonal | — | — |
| Tuzlaite | NaCaB₅O₈(OH)₂·3H₂O | Monoclinic | — | — |
| Tvalchrelidzeite | Hg₃SbAsS₃ | Monoclinic | — | — |
| Tvedalite | (Ca,Mn)₄Be₃Si₆O₁₇(OH)₄·3H₂O | — | — | — |
| Tveitite-(Y) | (Y,Na)₆Ca₆Ca₆F₄₂ | Trigonal | — | — |
| Tvrdýite | Fe²⁺Fe³⁺₂Al₃(PO₄)₄(OH)₅(H₂O)₄·2H₂O | Monoclinic | — | — |
| Tweddillite | CaSr(Mn³⁺₂Al)[Si₂O₇][SiO₄]O(OH) | Monoclinic | — | — |
| Twinnite | Pb₀.₈Tl₀.₁Sb₁.₃As₀.₈S₄ | — | 3.5 | — |
| Tychite | Na₆Mg₂(CO₃)₄(SO₄) | Cubic | — | 2.63 g/cm³ |
| Tyretskite | Ca₂B₅O₉OH·H₂O | — | — | — |
| Tyrolite | Ca₂Cu₉(AsO₄)₄(CO₃)(OH)₈·11H₂O | Monoclinic | 2.0 | — |
| Tyrrellite | Cu(Co,Ni)₂Se₄ | Cubic | — | — |
| Tyuyamunite | Ca(UO₂)₂(VO₄)₂·5-8H₂O | Orthorhombic | — | — |
| Tzeferisite | CaZn₈(SO₄)₂(OH)₁₂Cl₂(H₂O)₉ | Trigonal | — | — |
| Törnebohmite-(Ce) | Ce₂Al(SiO₄)₂(OH) | Monoclinic | — | — |
| Törnebohmite-(La) | La₂Al(SiO₄)₂(OH) | — | — | — |
| Törnroosite | Pd₁₁As₂Te₂ | Cubic | — | — |