18k gold is not "too soft" for a ring in the sense that it cannot be used or will not hold up over time; however, it is softer and more prone to scratching and denting compared to lower karat gold alloys like 14k or 10k. The higher gold content in 18k gold (75% gold and 25% alloyed metals) gives it a richer colour and greater value, but this also means it is less durable than its less pure counterparts, requiring more maintenance.