The Gold Lantern is a type of block from Reliquia. They are light sources which provide a light level of 15. There is a variant for all 16 standard Minecraft colors.
The adjacent blocks when placed determine which model to use— hanging from the ceiling; hanging from the wall; or sitting on the ground. Breaking blocks will not update its model. In order to obtain a vertical model, there can be no blocks on any side of the lantern when it is placed. In order to obtain the model for when it is on top of a block, along with empty adjacent blocks, there can be no block above it either. However, the model used is not saved to disk in any way, and as such, upon world reload, the model will reset to whichever model it determines should be used (using the checks described prior).
Three Gold Lanterns, showcasing the three different kinds of models available.
(Left to right) Lime; Red; Magenta