ðɪs ɪz θˈɔːt baɪ sˌʌm təbi kˈɔːzd baɪ slˈaɪt ɪmpjˈʊɹɹᵻɾiz ɔːɹ ˌæbɚɹˈeɪʃənz ɪnðə kɹˈɪstəl lˈæɾɪs, wˌaɪl ˈʌðɚz sədʒˈɛst dˈɪfɹənt ɛksplɐnˈeɪʃənz ɑːɹ nˈiːdᵻd.
This is thought by some to be caused by slight impurities or aberrations in the crystal lattice, while others suggest different explanations are needed.