The material is formed by heating silicon and sulfur or by the exchange reaction between SiO2 and Al2S3.
ðə mətˈɪɹiəl ɪz fˈɔːɹmd baɪ hˈiːɾɪŋ sˈɪlɪkən ænd sˈʌlfɜːɹ ɔːɹ baɪ ðɪ ɛkstʃˈeɪndʒ ɹɪˈækʃən bᵻtwˌiːn sˈiː ˈoʊ tˈuː ænd ˈæl tˈuː z θɹˈiː.