Bergman’s results is difficult to estimate. Tourmalines contain boron, but as the
nature of boric acid was much debated [3], there were no reasons for Bergman to
search for boric acid in a mineral. Baumé even claimed that borax could be obtained
from lard, which was disproved by Scheele.
The chemical nature of precious stones was examined by Bergman in a paper in
1780 [4]. These analyses were very challenging, as only very small samples could
be examined for economic reasons. Thus, it is perhaps not surprising that the
analytic results were less accurate and that he reported that both rubies and sapphires contain silica and lime, while they are in fact crystalline aluminium oxide.
Emeralds, which actually contain silicon, were reported to contain less siliceous
earth compared to rubies and sapphires, and the discovery of beryllium was left to
Vauquelin in 1798. Bergman also analysed topaz and hyacinth. Here, Bergman
could have discovered zirconium, an element discovered by Klaproth in 1789.
When analysing diamonds, Bergman found, correctly, that intense heat gave soot,
but he also erroneously reported a new earth, which he referred to as precious earth
or earth of gems.
25.2 Tin Sulphide Minerals
Bergman had received a collection of minerals from Siberia
1 , and among them there
was a sample that had the appearance of antimony covered with a golden substance
which was found to be tin(IV) sulphide (Aurum mosaicum) [5]. It was known that
tin formed two compounds with sulphur, one black substance containing about 20%
sulphur (SnS; 21% sulphur) and a gold-coloured substance containing about 40%
sulphur (SnS 2 ; 35% sulphur) and although both sulphur and tin were frequently
encountered in Earth’s crust, no one had, according to Bergman, previously
reported naturally occurring tin sulphides.
25.3 Mineralogial Remarks
Bergman’s last paper is a collection of discussions and analyses of mineral samples
sent to him by international friends and colleagues during the past couple of years.
The paper has the subtitle “first part”, but unfortunately, it would be Bergman’s last
published work. According to Crell [6], Bergman had finished the paper just 2 days
before his death, but considering Bergman’s condition the days before his death
(Sect. 28.1), this seems unlikely.
Bergman had predicted [7] that barium carbonate would be discovered as a
mineral, and English scientist William Withering (1741–1799), best known for
discovering the medical effects of foxgloves (Digitalis), had found such a mineral in
Scotland the previous summer. A sample sent to Bergman had not arrived, but
1
There is no mention of who had sent him the samples.
344
25 Bergman’s Contributions to Mineralogy
nature of boric acid was much debated [3], there were no reasons for Bergman to
search for boric acid in a mineral. Baumé even claimed that borax could be obtained
from lard, which was disproved by Scheele.
The chemical nature of precious stones was examined by Bergman in a paper in
1780 [4]. These analyses were very challenging, as only very small samples could
be examined for economic reasons. Thus, it is perhaps not surprising that the
analytic results were less accurate and that he reported that both rubies and sapphires contain silica and lime, while they are in fact crystalline aluminium oxide.
Emeralds, which actually contain silicon, were reported to contain less siliceous
earth compared to rubies and sapphires, and the discovery of beryllium was left to
Vauquelin in 1798. Bergman also analysed topaz and hyacinth. Here, Bergman
could have discovered zirconium, an element discovered by Klaproth in 1789.
When analysing diamonds, Bergman found, correctly, that intense heat gave soot,
but he also erroneously reported a new earth, which he referred to as precious earth
or earth of gems.
25.2 Tin Sulphide Minerals
Bergman had received a collection of minerals from Siberia
1 , and among them there
was a sample that had the appearance of antimony covered with a golden substance
which was found to be tin(IV) sulphide (Aurum mosaicum) [5]. It was known that
tin formed two compounds with sulphur, one black substance containing about 20%
sulphur (SnS; 21% sulphur) and a gold-coloured substance containing about 40%
sulphur (SnS 2 ; 35% sulphur) and although both sulphur and tin were frequently
encountered in Earth’s crust, no one had, according to Bergman, previously
reported naturally occurring tin sulphides.
25.3 Mineralogial Remarks
Bergman’s last paper is a collection of discussions and analyses of mineral samples
sent to him by international friends and colleagues during the past couple of years.
The paper has the subtitle “first part”, but unfortunately, it would be Bergman’s last
published work. According to Crell [6], Bergman had finished the paper just 2 days
before his death, but considering Bergman’s condition the days before his death
(Sect. 28.1), this seems unlikely.
Bergman had predicted [7] that barium carbonate would be discovered as a
mineral, and English scientist William Withering (1741–1799), best known for
discovering the medical effects of foxgloves (Digitalis), had found such a mineral in
Scotland the previous summer. A sample sent to Bergman had not arrived, but
1
There is no mention of who had sent him the samples.
344
25 Bergman’s Contributions to Mineralogy