Heart of gold

Saying a loved one has a ‘heart of gold’ is high praise. A compliment of Shakespearean origins, ‘heart of gold’ signifies the person is kind and honourable. Similarly, deeming someone ‘as good as gold’ means they are genuine, reliable and well-behaved. Trade the gold in both idioms for arsenic, lead or thallium, and praise becomes poison. The toxicity of these other semi-metals and metals is so well known that ‘heart of lead’ or ‘as good as arsenic’ would be widely recognised as grievous insults. For those persons held close to our hearts, gold-themed descriptions bestow the glittering qualities of the metal to the individual and relationship – splendour, stability and safety.

Bulk gold is considered safe because it is one of the least reactive metals. (Nano gold is weird. The fate and toxicity of gold nanoparticles are still challenging questions to answer.) Gold metal is impervious to various forms of chemical corruption that would consume lesser metals, earning its noble metal moniker and making it ideal for currency. For its shine and statement of status, pure gold has adorned weaponry throughout history – for style, rather than substance. Metallic gold, for all its superior qualities, is too soft for heavy combat.