The style of carving, subject, and choice of stone point to Allessandro Masnago who worked in Milan around 1600, often on commission from the Emperor Rudolf II in Prague and from other courts north of the Alps. This piece is said to come from the collection of the dukes of Bavaria.
The artist was famous for exploiting the colors of semi precious stones for these tiny, precious narrative images that were so popular with collectors. This composition, featuring a line of animals on the gangway to Noah's ark, is based on a woodcut by the French book illustrator Bernard Salomon (ca. 1508-1561) and was a favorite of the artist's.
<bdi>Possibly <a href="https://en.wikipedia.org/wiki/en:Allessandro_Masnago" class="extiw" title="w:en:Allessandro Masnago"><span title="Italian sculptor">Allessandro Masnago</span></a>
</bdi>
circa 1600 <div style="display: none;">date QS:P571,+1600-00-00T00:00:00Z/9,P1480,Q5727902</div> (<a href="https://en.wikipedia.org/wiki/en:Baroque" class="extiw" title="w:en:Baroque"><span title="cultural movement, starting around 1600">Baroque</span></a><div style="display: none;">era QS:P2348,Q37853</div>)
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