In fact, there are many explanations for the whopping blue diamond ring price. For one, natural blue diamonds are very rare. Note that only a few diamond ring vendors get to see the real blue diamond rings. In fact, most manufacturers create fancy blue diamonds because of their rarity. Sadly, only a few of them succeed in creating good gem-quality blue diamonds. So, some people may use sapphire stones instead of natural blue diamonds.
The price of a 0.25 ct blue diamond ring usually ranges from $1,700 to $2,500. This is actually the least diamond size that you can consider for a solitaire ring. The average size of an engagement diamond ring is usually regarded as 1 ct in the US, which means that the amount you will have to spend on a good blue diamond engagement ring may range from $5,000 to $12,000.