Tennant was investigating platinum metal samples and dissolved some samples in aqua regia. Aqua regia is an acid that is a mixture of nitric acid and hydrochloric acid and is useful for dissolving noble metals. When he dissolved his sample, a black powder would be left behind. He discovered this powder had different properties from platinum and was actually a mixture of two new elements. The first element formed salts that would shine with many different colors. He named the element iridium, after the Greek goddess Iris who was symbolized by a rainbow. The second element gave off a strong pungent odor so he named it osmium from the Greek osme which means 'odor'.
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