The diamond symbolizes ascension, clarity and wisdom. The exact meaning can differ between cultures and religions. For example, Native Americans from Canada, Mexico and North America see the diamond as the butterfly and it signifies immortality.
From an alchemist's perspective, the diamond signifies refracting light. This translates into the soul taking a journey to achieve higher understanding to reach clarity and enlightenment. At the end of the path, the soul will sparkle and shine like a diamond. This stone is also the April birthstone and in this sense, it stands for love, strength, eternity and everlasting affection. These meanings are also what make a diamond the primary stone for wedding and engagement rings.