These are 14kgf earrings featuring natural sky blue topaz and white topaz. They are November's birthstone. Sky blue topaz is the name given to the lightest blue shade of blue topaz, resembling the color of the sky. The refreshing Swiss blue topaz is a popular and classic color that appeals to a wide range of people. The back is cut in a conical shape, with the same facets as jewelry, allowing it to efficiently capture and reflect light, making the gemstone sparkle beautifully. *As these are natural stones, inclusions and cracks may be visible, but these are signs of their growth over many years, and we hope you will enjoy them as part of their character. All metal fittings and hooks are made of 14kgf material. [Swiss Blue Topaz] November Birthstone Stone Meanings: "Sincerity," "Intelligence," "Inquisitiveness" Size: Stone Size: Oval shape, approximately 8mm x 6mm, thickness approximately 4mm ... (likely a typo, possibly "drop" or "diameter" was intended) ■ All metal fittings and earrings are made of 14kgf material. [What is 14kgf?] It is a material made by bonding a layer of gold to a base metal such as brass under high heat and pressure. Gold-filled is the term used when the weight of the gold layer is 1/20 (5%) or more of the total weight, including the base metal. It is also known as gold-filled. The gold used for bonding is 14 karat gold, hence the notation 14kgf. It is a material that allows you to easily enjoy the brilliance of 14 karat gold and is considered to be more durable than plating. *Available options: Screw-back earrings, non-hole earrings, hoop earrings, and French hooks. Please comment if you would like these options; they will be made of brass gold plating or resin material.