Chrysoprase in Culture
As far as the metaphysical value of chrysoprase, it is said to encourage hope, joy, ease restlessness, and even give protection when traveling on the ocean. Hildegarde von Bingen, the 12th century abbess and mystic, prescribed chrysoprase for gout, calming anger, and reversing bewitchments. Alexander the Great, who lived in the 4th century BC, is said to have won his wars with a chrysoprase inlaid on his belt; when a snake bit the stone off his belt, he suffered military losses and never won another battle - or so the legend goes.
If you are familiar with Europe in the 1700s, or even stories such as the Hunchback of Notre Dame, you aren't surprised that public hangings were fairly frequent! Chrysoprase was said to bestow invisibility when placed in the mouth, so criminals were said to slip a piece of chrysoprase between their lips as they approached the gallows. However, I can't find any record of this plan succeeding!