The Montblanc Black Diamond is among the most spectacular writing instruments in the brand's history: the fountain pen is set with 4,810 diamonds – the number references the height of Mont Blanc in metres and is also the code of the Montblanc gold nibs. It thus joins the small group of ultra-high-end editions with which Montblanc underlines its position as the most exclusive writing instrument manufacturer.
The retail price of the Diamond writing instruments was around 100,000 to 125,000 euros per piece. Anyone who buys such a piece does so primarily out of collector or status interest – as an investment the edition cannot be recommended, since the gap between list price and actual resale value is considerable.
Concrete examples show this clearly: one Black Diamond changed hands second-hand for around 16,000 euros; another piece achieved approximately 20,000 euros. At Christie's, "A Royal Black Diamond Fountain Pen" came under the hammer with a result in the same range – that is, at less than one-fifth of the original retail price. Comparable auction results can be researched via Christie's lot database (e.g. christies.com/lotfinder, search term "Royal Black Diamond Fountain Pen").
For collectors this means: such diamond editions are undeniably luxurious and impressive from a craftsmanship point of view, but they are not suitable as a store of value. Anyone looking for value stability is generally significantly better served by classic limited editions or selected vintage pieces.
Related pages on fountainpen.de:
• Montblanc Meisterstück Royal (diamond edition, comparable piece with ~4,200 diamonds): fountainpen.de/solitaire-royal-en.htm
• Overview of all Skeleton editions: fountainpen.de/skeleton-en.htm
• Overview of Annual Editions: fountainpen.de/annual-editions-en.htm