Basic Information
The Seal of Solomon (also the Ring of Solomon) is a public domain artifact associated with the biblical King Solomon (although much of the lore concerning the ring comes from non-canonical Jewish and later medieval Arab sources). This artifact was said to consist of a signet ring made of brass and iron with the seal engraved on it by divine power. Solomon was said to have received the ring as a gift from heaven and found that it gave him authority over various spiritual entities (various jinn, demons, devils and others), both by direct command and by using the seal of the ring to create edicts and containments that could bind them (and thus being the traditional source of jinni in bottles). Some traditions also suggest that the ring gave him the ability to understand the speech of birds and animals.
As usual, there is also a certain amount of subversion around this artifact - mostly related to incidents in which some demon is said to have stolen the ring and displaced Solomon for a time, ruling in his stead.
Notably the name "Seal of Solomon" is also applied to a variety of pentacles said to be derived from the original seal and almost universally featuring a multi-pointed star as a prominent element. These pentacles are a particular favourite for the creation of amulets in the Hebrew tradition.