This paper presents the mineralogical characterization of 56 sherd samples from the Börükçü site in Muğla, Turkey. Principal component analysis (PCA) employing raw attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectra (825–400 cm−1) with 17 smoothing points discriminated the sherd samples into five different groups (A–E). The second-derivative ATR-FTIR spectra (two polynomial degrees and 11 smoothing points) between 1700 and 400 cm−1 were successfully used to assess the firing conditions. The obtained results showed that the firing temperatures are about 600–800°C for sherd groups A, C and D and about 800–950°C for sherd groups E and B.