The price of blue onyx stone varies depending on several factors, including the uniformity of its color and pattern, the size of the stone, and its overall quality. Blue onyx stones that exhibit a consistent and uniform color throughout the slab tend to be more valuable and may command a higher price. Additionally, larger-sized blue onyx stones are generally more expensive due to the increased material required and the potential for larger, uninterrupted patterns. The quality of the stone, including its clarity, translucency, and any unique characteristics, can also influence its price. Other factors such as market demand, availability, and the reputation of the supplier or quarry can also impact the pricing of blue onyx stone.