THe Haüyne
Haüyne has a complex history that is emblematic of new minerals discovered during the 19th century. It was originally named "lazialite" by Carlo Guiseppe Gismondi (1762-1824) who found it in the vicinity of Albano, at Lake Nemi in Lazio, south-east of Rome (Italy). Its chemistry was promptly inferred in Rome.
His report was sent to the Lincei Academy of Sciences in 1802 was not published. Haüy received (at least) three samples kindly sent by Gismondi. Haüy renamed it "latialite" maybe because (1) « laziolite » would have been more logical and (2) because "Lazio" in Latin or French translates as "Latium".
But, in 1807, the Danish mineralogist Tønnes Christian Bruun de Neergaard (1776-1824) finds this mineral also in Vesuvius and in the Eifel (Germany): it is not any more endemic of the Lazio hills. Its name becomes then incoherent and it must be renamed in the honor of Haüy.
Neergaard (selfportrait)
© Det Kgl. Biblioteks/wikimedia
Moreover, in his Traité de minéralogie (II, 1822, p. 338), Haüy honors Bruun's "science" except for the name:
The Haüy collection bears " latialites" from France (Cantal, Puy-de-Dôme) and Germany (Anderbach, Closterlach, Niedermenich) showing this mineral quickly became not that endemic anymore from the Lazio as Gismondi had believed. Still, Haüy never endorsed the name of haüyne in his collection and that he persisted in naming them "latialite" (instead of "lazialite"). "Haüyne" was eventually added as a title of this inventory when it was re-edited shortly after 1848.
Distinguishing between lazurite and haüyne have always been difficult since the 19th century. A 2014 study (here) showed that lazurite is rare in nature and that many specimens called "lazurite" are, on the contrary, rather composed of haüyne, especially those of Afghanistan while lazurite is newly defined (read here, the original in Russian or here its translation into English).
Some, like Gian Carlo Parodi (MNHN), disagree with these studies but these controversies have not yet been published.
It could be the same for lapis lazuli which is a rock essentially composed of haüyne (or lazulite, as you wish...) alongside sodalite, pyrite and calcite.
The two samples of haüyne (formerly Gismondi's lazialite or Haüy’s latialite) from the vicinity of the lake of Nemi-Albano (Lazio) sent by Gismondi to Haüy. The one on the right is the official IMA cotype (inv. 2395 (Haüy)) but does not come from Vesuvius (as specified by the IMA) but from Lazio as its label still indicates (below). Scale bar is 1 cm.
Paris, MNHN, collection Haüy. Photos: F. Farges, ©MNHN.
Polished plate of lapis lazuli from Tajiskistan. Height: 42 cm. Paris, MNHN, minéralogie. Photo and gift : F. Farges, ©MNHN.
Haüyne crystals (formerly lazurite or still lazurite for some mineralogists) in marble with pyrite and molybdenite. Sar-e-Sang, Afghanistan. Length: 28 cm. Paris, MNHN, minéralogie. Photo: F. Farges, ©MNHN.
Facetted haüyne (Eifel, Germany), 0,2 carats. Paris, MNHN, minéralogie. Photo: F. Farges, ©MNHN.
Haüyne, lazurite and lapis lazuli: what a mess!
The type- sample and locality
IMA cites that the holotype of the haüyne is sample inv. H2395ff is from Vesuvius. But this inventory number does not exist; it is (Haüy) 2395 (as shown above). Moreover, thanks to the 1849 catalogue, 2395 is NOT from Vesuvio but from Lake Nemi via Gismondi :
Some of these discoveries were exhibited and published in 2020-2021 during the "Gems" exhibition in the lapis lazuli showcase:
The types of haüyne
Moreover, one cannot really speak about holotype concerning inv. (Haüy) 2395 (or inv. (Haüy) 2401 or 13.36) because the original Gismondi sample has not been formerly identified if it survived. At least, the MNHN keeps 3 co-types of lazialite/latialite/haüyne sent by Gismondi from the Albana-Nemi area.
Showcase of the "Gems" exhibition (2020-2021) dedicated to lapis-lazuli showing the progression from massive forms (bottom, Tajikistan) to crystalized forms (Afghanistan) then worked (snuffbox lid) then mounted (top, Van Cleef&Arpels necklace).
Note the official type sample of haüyne (Haüy) 2395 (red arrow), sent by Gismondi to Haüy
The two largest specimens spnt detailed below.
Paris, MNHN, minéralogie. Photo: J.C. Domenech, ©MNHN.
Carlo Guiseppe Gismondi
Another type sample of haüyne (as seen from two viewpoints) from the MNHN (inv. 13.36) donated 1803 by Gismondi from the official MNHN collection. The label is 20th century. Scale bar is 1 cm. Paris, MNHN, collection Haüy. Photos: F. Farges, ©MNHN.
It was strangely catalogued as "haüyne" (right) or " lazurite ?" (below), from Albano, south of Rome, and then corrected to haüyne in the 20th century:
A third sample was given by Gismondi to Haüy which the latter retroceded to the official MNHN collection because it was the richest of the three:
The cotypes of haüyne from Vesuvius by Bruun have not (yet) been formally identified as well (if they still exist). Still, the Haüy collection possess several samples from the Vesuvio incl. via Sementini, Weiss or Thomson and two from undeclared provenance, including the very first of all haüynes of Haüy’s collection, i.e., inv. 2394). Anyhow, IMA will be notified soon to correct their listings.
I said that the first description of the haüyne was due to M. Gismondi. Mr. Neergaard, taking advantage of the observations that this scientist had communicated to him, and to which he added several of his own, has made, from one and all, the basis of a memoir, where everything is dictated by science, except for one name which can only have been dictated by friendship.
Two "latialite" samples from Albano-Nemi Lake area sent by Gismondi are still kept in Haüy’s collection, numbered 2395 and 2401 (both Haüy):
We do not know if fragments from the above three samples served the chemistry analyzes by Vauquelin or if the fourth sample send by Gismondi was only analyzed. For us at the MNHN, this sample is the first of the 3 haüyne (lazialite/latialite) cotypes from Gismondi.
original label for (Haüy)2395 where the text is barely readable except Gismondi
Nicolas Vauquelin
In his thorough studies, Nasti mentions that the type specimen of haüyne is MNHN H2395ff from the Vesuvio according to IMA. Nasti suspected something wrong : actually, IMA is indeed wrong as H2395ff does not exist at the MNHN but 2395 (Haüy) that is from the Lake Nemi (see below ; IMA correction is underway).
Further, they are not one but three cotypes from Gismondi/Lazio at the MNHN as shown now.
For me, a mineral dedicated to the Lazio should not be called « lazialite » (= stone from Lazio/Latium as this species was also found elsewhere, like the Vesuvio as Gismondi knew) but "laziale" (like violane, noseane, celestine ...)
More importantly, Haüy quickly noticed that its chemistry performed in Rome was missing something. So Nicolas Vauquelin, at the MNHN, completed the missing analyzes based on a fourth specimen shipped by Gismondi, weighting 2 grams that disappear in the flasks for wet chemical analyses.
Scientists grateful for the huge discoveries made by Haüy (though retired!) dedicated a mineral to him, even though it bothered this modest person.