Hierarchy of precious substances

In popular culture, sets of precious substances may form hierarchies which express conventional perceived relative value or . Precious metals appear prominently in such hierarchies, but as they grow, gems and semi-precious materials may be introduced as part of the system. The sequences can provide interesting examples of the arbitrariness of semiotic signs.

Jubilees have a hierarchy of years: silver (25 years), ruby (40), golden (50), followed by diamond (60), sapphire (65), and platinum (70). Wedding anniversaries extend the jubilee hierarchy with various sequences of substances filling in many of the gaps between the same major milestones.

Ancient Greek mythic-cultural cosmology depicted a decline from a golden age to a silver age followed by an Iron Age.

The measurement of sales of popular music starts high relative to the wedding anniversary scale, concentrating on gold and platinum (see gold album). Likewise, credit card companies usually have a "gold card" and a "platinum card" (many formerly had a "silver card" then followed by a "gold card", but due to similarity in appearance between silver and platinum these were often discontinued with the rise in popularity of platinum as a precious metal); Standard Chartered Bank has introduced a "titanium card" as a grade higher than platinum.

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