Sapphire is a gemstone from the mineral family corundum. Typically known for its deep blue color, sapphire is also available in a variety of color options including white, pink, orange, and yellow. With a Mohs hardness rating of 9, sapphire is second in hardness only to diamond, which makes this stone ideal for wedding jewelry.

Like sapphire, ruby is also from the mineral family of corundum and has a Mohs hardness rating of 9. Ruby is discerned from all other colors of sapphire by its red color.

Known for its vivid forest green color, emerald is the most valuable form of the mineral beryl. Emerald is a hard material, rating a 7.5–8 on the Mohs scale.

Alexandrite is a rare color-changing variety of the mineral chrysoberyl that can appear bluish-green in natural or fluorescent light, and brownish or purple-red in incandescent light. This gemstone rates an 8.5 on the Mohs scale. Since naturally mined Alexandrite is incredibly rare, lab-grown Alexandrite is a popular choice for its availability and significantly lower price point.