The copper mines of Phaeno
Eusebius of Caesarea, an eyewitness to the persecution in Palestine, places Silvanus among the confessors condemned to the copper mines of Phaeno, a settlement in the Arabian desert between Petra and Zoar whose mines were worked by convicts. The aged bishop, no longer fit for the labour, presided over a group of confessors who had been released from the heaviest work and who kept to fasting, prayer, and the customary observances of their faith.
According to Eusebius, the provincial governor reported the situation at the mines to the emperor, and on the orders of Maximinus the confessors who could no longer labour were put to death. Silvanus and his companions were beheaded in a single day, near the close of the roughly eight years of persecution in the province.