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What you say sounds reasonable, but the university PR claimed that they knew chromite was special >Crucially, analyses using Scanning Electron Microscopy enabl

What you say sounds reasonable, but the university PR claimed that they knew chromite was special >Crucially, analyses using Scanning Electron Microscopy enabled them to identify remains of the ore mineral chromite [rusakhtaj], which was described in Biruni’s manuscript as an essential additive to the process. https://www.ucl.ac.uk/news/2020/sep/chromium-steel-was-first-made-ancient-persia https://www.ucl.ac.uk/news/2020/sep/chromium-steel-was-first... This still doesn't say they knew about chromium ofc just that it was not just magnetite. Ofc one has to read farsi to make sure rusakhtaj wasn't a common alias for magnetite. Who knows, rudimentary awareness of the concept of "alloy" might have existed there..

adrian_b 1y ago
The original text would have to be read extremely carefully to conclude that they knew that chromite is really different from magnetite. I have read many ancient texts about metallurgy and the like, where they were using a bewildering amount of various names to designate the various kinds of ores and of produced metals. Despite that, they did not think that there was any essential difference between the many kinds of magnetite or of chalkopyrite and so on. They were habituated with the fact that the natural minerals extracted from different places have never exactly the same properties. Now we know that this is caused by slightly different chemical compositions, but they just knew that some are better for a certain purpose, while others are worse, without knowing why this is so. Because this is how all the minerals they knew had always behaved, it was not considered a surprising fact. It was just accepted that you have to know the exact origin of a mineral, to assess its value and its suitability for a desired purpose. So I doubt that they had considered chromite as a stone distinct from magnetite, like they considered e.g. magnetite distinct from pyrite, where the appearance of the stones is easily distinguishable. Even if they had thought that chromite is not a better kind of magnetite, but something really different, they still would have not imagined that chromite contains another metal that becomes alloyed with iron, like they knew to alloy tin with copper or the like. They would have thought that adding chromite stones to the minerals for iron extraction improves the resulting steel for some unknown reason.
- gsf_emergency_2 1y ago
  I'd imagine, by those days, they could tell chromite was significantly "less magnetic" than magnetite.. in principle of course.

adrian_b 1y ago

The original text would have to be read extremely carefully to conclude that they knew that chromite is really different from magnetite. I have read many ancient texts about metallurgy and the like, where they were using a bewildering amount of various names to designate the various kinds of ores and of produced metals. Despite that, they did not think that there was any essential difference between the many kinds of magnetite or of chalkopyrite and so on. They were habituated with the fact that the natural minerals extracted from different places have never exactly the same properties. Now we know that this is caused by slightly different chemical compositions, but they just knew that some are better for a certain purpose, while others are worse, without knowing why this is so. Because this is how all the minerals they knew had always behaved, it was not considered a surprising fact. It was just accepted that you have to know the exact origin of a mineral, to assess its value and its suitability for a desired purpose. So I doubt that they had considered chromite as a stone distinct from magnetite, like they considered e.g. magnetite distinct from pyrite, where the appearance of the stones is easily distinguishable. Even if they had thought that chromite is not a better kind of magnetite, but something really different, they still would have not imagined that chromite contains another metal that becomes alloyed with iron, like they knew to alloy tin with copper or the like. They would have thought that adding chromite stones to the minerals for iron extraction improves the resulting steel for some unknown reason.

gsf_emergency_2 1y ago
I'd imagine, by those days, they could tell chromite was significantly "less magnetic" than magnetite.. in principle of course.