Bring me sunshine
Nina Morgan delves into the history of a mineral that is helping to revolutionise the solar energy industry
Image by andreas160578 from Pixabay
Solar panels composed of thin silicon wafers stacked together inside a glass module are springing up in rooftops and factory sites everywhere. Although these already offer great advantages for producing renewable electricity, there’s still more to be done. The technology for conventional solar panels has improved so much over the last decade that modern solar panels are now approaching the theoretical limit of conversion efficiency. Developing tandem cells able to collect both the high and low energy parts of the solar spectrum offers a way forward. As it turns out, an ‘artificial’ manufactured version of the mineral perovskite (CaTiO3), deposited as a thin film coating on top of silicon wafers in solar cells offers a promising way to achieve this.
Natural perovskite
The naturally occurring mineral perovskite, a common accessory mineral in alkaline and basic igneous rocks, including mafic igneous rocks and pegmatites as well as chlorite or talc schists, is mined as a titanium ore in Switzerland, Italy, Arkansas and Russia. The first sample of this mineral was collected in 1839 in the Ural Mountains, Russia and transported from St Petersburg to Berlin in 1839 by August Alexander Kämmerer [1789 – 1858], the Chief Mines Inspector of the Russian Empire. He, in turn, gave the sample to the versatile German mineralogist, Gustav Rose [1798 – 1873] for further investigation. Rose quickly set about determining the physical and chemical properties of the sample, and published the first paper describing it that same year.
Perovskite from Magnet Cove, Arkansas, USA. Size: 5.0 x 4.1 x 1.2 cm. (Image credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0, CC BY-SA 3.0, via Wikimedia Commons)
Gustav Rose was well placed to take on the job. He came from a family with a strong tradition in science, especially chemistry – and Gustav was no exception. Among his many achievements, Rose was chosen in 1829 to accompany the German naturalist and geographer Alexander von Humboldt [1769- 1859] on a scientific journey to the Urals, the Altai Mountains in Mongolia, the Caspian Sea and the frontier of China. Rose’s two-volume chronicle of the journey, Mineralogisch-Geognostische Reise nach dem Ural, dem Altai und dem Kaspischen Meere, published in 1837 and 1842, includes extensive observations on geology, mineralogy, and mineral resources of the regions he visited. He also published around 125 papers covering nearly all aspects of mineralogy known at the time.
German mineralogist Prof Gustavus (“Gustav”) Rose [1798–1873]. (Credit: Museum für Naturkunde Berlin, Public domain, via Wikimedia Commons)
It seems to be a tradition amongst mineral ‘discoverers’ to name minerals as a tribute to other mineralogists. Thus, Kämmerer suggested Rose should name the ‘new’ mineral perovskite after Count Lev Alekseyevich Perovski [1792 – 1856], a mineralogist and Minister of Internal Affairs under Nicholas I of Russia.
In turn, Gustav Rose’s own mineralogical legacy was ensured when the French mathematician and mineralogist Armand Lévy [1795 – 1841] named a ‘new’ rose-red to pink arsenate mineral [Ca2(Co,Mg)[AsO4]2·H2O], first recognised in cobalt-rich mineral hydrothermal deposits in1825, roselite, after Rose. And so it goes on. The zeolite mineral levynite, or levyne, discovered in 1821, was named after Lévy in 1825 by the Scottish scientist David Brewster [1781- 1868] who is known, geologically, for his pioneering work in optical mineralogy.
Roselite from the Aghbar Mine, Bou Azzer, Morocco. Length: 6.2 cm. (Image credit: Jamain, CC BY-SA 4.0, via Wikimedia Commons)
Permanent memorial
Admittedly, roselite is not a household name, even amongst geologists, but Rose is also remembered in a more permanent and accessible way by his gravestone in the St Marien and St Nikolai I Cemetery in Berlin. Sadly, roselite is not a suitable material for gravestones. Instead Rose’s attractive gravestone is made of what appears to be rough cut and polished rose-coloured granite.
It’s fun to speculate on the choice of stone. A pun on his name perhaps? But when thinking about a how they’d like to be remembered, maybe all geologists should give this sort of detail some careful thought!
Author
Nina Morgan is a geologist and science writer based near Oxford, UK
Further reading
- ‘Gustav Rose’; Encyclopedia.com
- Katz, E.A. (2020) Perovskite: Name puzzle and German-Russian Odyssey of Discovery. Helva. Chim. Acta 103; https://doi.org/10.1002/hlca.202000061
- Morgan, N. & Grindley, G. (2024) The Future of Solar Power. WRFM Science on the Radio – Episode 66. Oxford PV; wrfm.co.uk/on-air/podcasts/science-on-the-radio/episode/wrfm-science-on-the-radio-episode-66-oxford-pv-the-future-of-solar-power/
- Rose, G. (1839) Beschreibung einiger neuen Mineralien des Urals. Poggendorffs Ann. Phys. Chem. 124, 551–573; https://doi.org/10.1002/andp.18391241205
