The Ring of Shen-marak is a religious relic that is in fact the power coil from an obsolete cargo ship. When Vala was making her way as a trader, smuggler, and thief, she encountered a fellow smuggler who had found religion and was posing as Brother Caius at a monastery. Vala had stolen a necklace from Arlos, which she traded to Inago for the power coil, and, pretending to be Sister Vesina, she had offered the power coil as a generous gift to Caius's monastery, where it became the legendary Ring of Shen-marak, a relic which pilgrims from all over the system traveled to see.
Coincidentally, at the time of her donation, the shrine's most precious relic, the Livanna Crystal, had mysteriously disappeared, making it a bittersweet season at the shrine. Vala had also "borrowed" Caius's cargo ship, to which he had made a few special modifications, and the ship was now in the possession of the Lucian Alliance.
When Vala and SG-1 sought help from Arlos to disengage the Kor Mak bracelets, Arlos demanded the return of his necklace, and Inago would only agree to cooperate if SG-1 returned his power coil in a straight swap, but Caius insisted that the pilgrims and their donations were the only thing keeping the shrine afloat, and the return of the priceless relic was out of the question. However, he had become desperate to escape the monastic life, and he was willing to make the trade only if his cargo ship was returned to him. SG-1 had to recover the cargo ship from the Lucian Alliance, exchange the ship for the power coil, and trade the power coil to Inago for the necklace, which they then returned to Arlos. The legendary Ring of Shen-marak was no more.
Cross Reference: Caius
Episode Reference: The Ties That Bind