wˌɛn hˈiːɾᵻd tə sˈɛvənhˈʌndɹɪd dᵻɡɹˈiːz sˈiː, ˈɪndiəm ɹˌoʊmən θɹˈiː ˈɑːksaɪd fˈɔːɹmz ɪn tˈuː ˈoʊ, kˈɔːld ˈɪndiəm aɪ ˈɑːksaɪd ɔːɹ ˈɪndiəm sʌbˈɑːksaɪd, æt tˈuː θˈaʊzənd dᵻɡɹˈiːz sˈiː ɪt dˌiːkəmpˈoʊzᵻz.
When heated to 700 °C, indium(III) oxide forms In2O, (called indium(I) oxide or indium suboxide), at 2000 °C it decomposes.