When selecting aquamarine, the most prized stones are those with a deep, clear blue hue, free of green or grey undertones. The gemstone should be eye-clean, meaning it has no visible inclusions. Larger stones tend to have more intense colours, which can increase their value. Aquamarine is a durable stone, making it suitable for everyday wear, but it is important to protect it from harsh chemicals and sharp impacts. Be sure to verify the origin of the stone, as certain sources, like Brazil, are known for producing higher-quality aquamarine.