One can distinguish at least three major strands, which appear to be mostly independent, at least in their earlier stages: Chinese alchemy, centered in China; Indian alchemy, centered on the Indian subcontinent; and Western alchemy, which occurred around the Mediterranean and whose center shifted over the millennia from Greco-Roman Egypt to the Islamic world, and finally medieval Europe.
wˈʌn kæn dɪstˈɪŋɡwɪʃ æt lˈiːst θɹˈiː mˈeɪdʒɚ stɹˈændz, wˌɪtʃ ɐpˈɪɹ təbi mˈoʊstli ˌɪndᵻpˈɛndənt, æt lˈiːst ɪn ðɛɹ ˈɜːlɪɚ stˈeɪdʒᵻz: tʃaɪnˈiːz ˈælkəmi, sˈɛntɚd ɪn tʃˈaɪnə; ˈɪndiən ˈælkəmi, sˈɛntɚd ɔnðɪ ˈɪndiən sʌbkˈɑːntɪnənt; ænd wˈɛstɚn ˈælkəmi, wˌɪtʃ əkˈɜːd ɚɹˈaʊnd ðə mˌɛdɪɾɪɹˈeɪniən ænd hˌuːz sˈɛntɚ ʃˈɪftᵻd ˌoʊvɚ ðə mɪlˈɛniə fɹʌm ɡɹˈiːkoʊɹˈoʊmən ˈiːdʒɪpt tə ðɪ ɪslˈɑːmɪk wˈɜːld, ænd fˈaɪnəli mˈɛdɪˌiːvəl jˈʊɹɹəp.