The 'Jet' Brooch
Maud Bailey was wearing a 'Jet' Brooch heirloom during the latter day couple's visit to 'Whitby' in Yorkshire (England). Whilst there, they visited a shop that dealt in artefacts crafted from a Black, Semi-Precious, Fossil Stone called 'Jet'.
http://www.yorkshirecoastfossils.co.uk/what%20is%20whitby%20jet.htm
For those who weren't aware, The website above will enlighten you as to where the descriptive expressions, 'Jet Black' or 'Black as Jet' originated. A 'Jet' Brooch was a classy clothing accessory for 'Victorian' ladies to wear at funerals. Queen Victoria herself wore one at the funerals of 'Lord Wellington' and her own husband 'Prince Albert'.
"Black As Jet"
"Ah! Black as jet, but long ago
Indignity and lace,
The Ladies wore around their necks
A flash of ebon grace.
But oh! To-day Great Broughton mourns,
Still waves the merry corn,
The beer flows at Jet Miners' Inn,
But jet's no longer worn.
Still, fashions change, mayhap some day
Again the craft will thrive,
And Yorkshire jet will ring the earth,
Black, flashing and alive."