In the Middle Bronze Age, an apparently "alphabetic" system known as the Proto-Sinaitic script appeared in Egyptian turquoise mines in the Sinai peninsula dated  15th century BCE, apparently left by Canaanite workers.
ɪnðə mˈɪdəl bɹˈɑːnz ˈeɪdʒ, ɐn ɐpˈæɹəntli "ˌælfəbˈɛɾɪk" sˈɪstəm nˈoʊn æz ðə pɹˈoʊɾoʊsɪnˈeɪɾɪk skɹˈɪpt ɐpˈɪɹd ɪn ɪdʒˈɪpʃən tˈɜːkwɔɪs mˈaɪnz ɪnðə sˈaɪnaɪ pənˈɪnsjʊlə dˈeɪɾᵻd fˈɪftiːnθ sˈɛntʃɚɹi bˌiːsˌiːˈiː, ɐpˈæɹəntli lˈɛft baɪ kˈænɑːnˌaɪt wˈɜːkɚz.