A range of the highest quality and most valued naturally-colored Akoya pearls is called Hanadama. It is the Japanese word for spherical flower. Strands of pearls of this extraordinary quality are objectively graded by the Pearl Science Laboratory of Japan, and a numbered Hanadama Certificate must accompany each strand.
These pearls are tested for the following attributes:
- Luster. Must be very strong.
- Nacre thickness. Must have a minimum of 0.8mm total nacre.
- Near flawless surface. Only one “deep” inclusion per strand allowed.
- Proof of Aurora Effect or Orient. This is the iridescent “soap bubble” shimmer seen only on the finest pearls. Orient is possible only with thickly layered and tightly compacted crystalline nacre. When light strikes and penetrates the nacre layers, it breaks into a spectral rainbow of colors that bounce back at the viewer.