MOURNING & SENTIMENTAL
Mourning jewellery was often a little macabre, depicting 'Memento Mori' - 'Remember you must die' symbols of skulls and full skeletons, coffins and the Latin phrase inscribed itself. Pieces we often crafted in Yellow gold black materials, lacking in colour until the later stages of mourning when these could be introduced again, showing the stages of grief that the wearer was going through. Most commonly used was jet, a fossilised coal, or other inexpensive alternatives including black enamel and glass. Black gemstones such as Onyx were also common. Popularised in the 1800's by the loss of Price Albert to Queen Victoria, black jewellery gained in popularity.
Sentimental Jewellery was often worn and exchanged during one's lifetime, and not in their passing. Pieces were full of symbolism- like the horseshoe for good luck- and hidden messages and meaning, such as the spelling of a lover's name hidden in plain sight, coded by the colouring of the gemstones and their individual names, taking each 1st letter to reveal it.
[Side note: One of my favourite non-jewellery examples here if you have yet to read it, is the poem 'A Valentine' by Edgar Allan Poe. The name is revealed by reading the 1st letter of the 1st line, the 2nd letter of the 2nd line, and so on. Immerse yourself in an antique copy (which you can pick up quite commonly- because old books smell the best) to discover and uncover the name!]
I personally favour the combination of a rich, warm yellow Gold against the depth a black stone like a black diamond or onyx, and regularly pair this beautiful contrast in my collection pieces.