In this final instalment of ‘Show Me Your Metal’, we shall look at four metallic elements which were not known to the ancients, but whose names were taken from Latin or Greek and which reflected one of their features or properties.
Lanthanum (La): This element comes in at 57 on the Periodic Table. This metal is a rare element and hard to discover, which, as we shall see, explains how it got its name. It was discovered through extractions from the mineral cerite. Mosander first discovered didymium mixed with cerite, which he separated into two different types in 1885. Cerite had first been discovered in 1751. Lanthanum’s turn had to wait until 1923, when it also was extracted from cerite. It had taken longer to find; it ‘lay hidden’ all this time. The name comes from the Greek ‘to escape notice’ (λανθάνειν). The element ‘krypton’ also takes its name from a Greek verb relating to being hidden (κρύπτειν – to hide), similarly reflecting its quality of being hard to discover (unless Superman’s in the way, oh, wait a bit that’s kryptonite!).
Tellurium (Te): Tellurium is a metallic element that is silvery-white in colour and toxic, but mildly so.1 The name comes from the Latin tellus meaning earth, and Tellus would often be personified as a deity of the earth and nature.2 It was discovered in a gold ore. The other metal in the ore was found to be very similar to antimony, but was clearly a different element, named Tellurium by scientist Martin Klaproth, but discovered by von Reichenstein and Kitaibel independently of one another.3
Selenium (Se): Some do not class Selenium as a metal, but this is rare, but is perhaps due to the fact that it shares properties with non-metallic element sulphur and is often discoverable in sulphide containing ores. However, let us turn to its rather beautiful name. It is the partner metal of tellurium to which it is very similar (particularly in the horseradish like odour it omits when burned). Tellurium, as we saw, was named after the earth, so its similar metal was christened after the moon, using its Greek name selēnē (σελήνη). The name was coined by Swedish scientist Jӧns Jacob Berzellus.
Promethium (Pm): So, finally in this series, we come to the Titan element, and, yes, it is significant that this element takes its name from the titan Prometheus. It is a highly radioactive metal and is a member of the lanthanides (yes, the elements that ‘lay hidden’, a property shared by Lanthanum, the first in this article). It is no accident that this powerful, but volatile, element is named after the titan who stole fire for mortals’ benefit…and destruction. It reflected the fears felt over its possible misuse by humans and was suggested by Mary Coryell, wife of one of the element’s discoverers, Charles D. Coryell. Humans can use and they can abuse. The name is thus rather aptly applied to a potentially dangerous atomic element.4
(1) It is a member of the chalcogen* family of elements (from the Greek χαλκος (copper, bronze, or more generally 'metal' and γεν being from the stem of the verb γίγνομαι (arise, be born, be formed)). The name means ‘ore forming’, and this group contains both metallic and non-metallic elements, the metallic possessing properties normally associated with non-metals. For more on the chalcogens, see Emsley, John (2011). Nature's Building Blocks: An A-Z Guide to the Elements (New ed.).
(2) On the famous Tellus frieze of Augustus’ Ara Pacis, see https://www.britannica.com/topic/Ara-Pacis.