It depends on your budget and style preference. Many people opt for a 1 to 1.5-carat diamond or gemstone as the center stone, offering a nice balance of presence and everyday wearability.
Keep in mind that carat does not equal sizeβ The size of the gemstone is the length and width of its top side, while the carat weight is the weight of the entire stone. Sometimes, the stones will be different sizes for the same carat weight, which results in some appearing larger and others smaller in the same carat. It depends on cut depth. For more details, refer to our Gemstone Cut Depth Guide.
So, you should look at these two elements together when choosing a center stone.