貝

It is an ideogram (pictograph) modeled after the shape of a shell with two clam shells.

Before metal and paper money were invented, shells (specifically clam shells) were used as currency, which is why many characters containing the radical 貝 relate to money, wealth, and economics.

貝 acts as a semantic indicator related to money and valuables in many Chinese characters.

Examples:

買 (to buy)

賣 (to sell)

貴 (valuable, precious)

賤 (lowly, cheap)

財 (wealth, property)

貧 (poor)

貪 (greedy)

賃 (wage, rent)

貨 (goods, money)

貸 (to lend)

責 (to blame)

賊 (thief)

質 (substance, quality)

貯 (to store)

賢 (wise)

貢 (to offer, tribute)