# What explains the very high density of osmium and iridium? [duplicate]

Iridium with a density of $22.56$ g cm-3 & osmium with $22.59$ g cm-3. Data from their respective Wikipedia pages.

Only these two naturally occurring elements have such a high density. I wish to know why. Also If possible the factors affecting the density of any/every elemental substance.

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• Well, by definition, at least one element will be the densest. So you are asking why particular elements adopt a close-packed crystal structure (various reasons) and have heavy nuclei. I'm not sure that there is a 'simple' explanation for that. – Jon Custer Dec 14 '15 at 14:25
• The reasons behind osmium's density are explained here – ron Dec 14 '15 at 14:26