While not considered to be an imitation of jet (as is often the common misconception), bog oak is a material used quite often in sentimental jewels and is visually similar in both its colour and by carving to jet that it’s worth having a look at. Much of its popularity comes directly from the demand of jet itself in the 1870s, which was large enough to provoke its imitators (vulcanite) and rivals such as bog oak.
Hailing from Ireland, bog oak designs often present Irish motifs, such as the shamrock and harp, but often castles are carved into brooches. It is a fossilised wood and quite easily carved.
Spotting bog oak jewellery can be somewhat difficult to the untrained eye, but it doesn’t take a high polish like jet, is actually dark brown and shows a wooden patina. Testing should not be necessary for bog oak, its style and construction is much more relative to its material.