No, but it depends on quality, all gems are classed by the four Cs, clarity, colour, cut, and carat ( size ) if a stone is perfect it’s a triple A stone and the larger the more expensive, they are weighed by carats and points, ( 100 points per carat ) if a stone is 130 points, it’s 1.3 carats. Like this sapphire it’s 500 points = 5 carats