#15: The Aleppo Codex (c. 920 AD)
For centuries considered the most authoritative Hebrew Bible in existence, meticulously annotated by scholar Aaron ben Moses ben Asher, the Aleppo Codex was housed in Syria for over 600 years before roughly 40 percent of its pages disappeared during riots in 1947. The surviving portion is held by the Israel Museum in Jerusalem and has never been sold. Scholars estimate its value, were it ever to come to market, would exceed any manuscript ever auctioned.

