kɹˈɪptəkɹˌɪstɐlˌaɪn sˈɪlᵻkˌeɪts, sˈʌtʃ ɐz flˈɪnt ænd tʃˈɜːt, ɑːɹ sˈʌmtaɪmz hˈiːttɹˈiːɾᵻd ɪn ˈɔːɹdɚ tʊ ɪmpɹˈuːv ðə flˈeɪkɪŋ pɹˈɑːpɚɾiz ʌvðə mətˈɪɹiəl.
Cryptocrystalline silicates, such as flint and chert, are sometimes heat-treated in order to improve the flaking properties of the material.