Golden Kanohi

"Then there was a peal of sound, like great bells blended with laughter. Onua gasped in amazement as a new mask suddenly appeared on the face of each stone carving--a golden Kanohi, glowing with light and power. Onua carefully lifted the golden Kanohi from the carving's face and placed it on his own. He staggered back a step as waves of power blasted through him. Then he smiled. This united all the powers of the other six--only it was even stronger!"

- Narration, BIONICLE Chronicles 1: Tale of the Toa

Golden Kanohi were incredibly powerful and unique Kanohi Masks, which allowed the wearer access to six powers at once, though only one could be actively used at a time.

History
These Kanohi appeared only once, when the Toa Mata collected their Great Masks, brought them to the Kini-Nui, and placed them onto life-sized carvings of themselves. They wore these masks when they fought and defeated Makuta Teridax and the Bohrok swarms, but when they became Toa Nuva the Golden Kanohi ceased to exist. Takua also once discovered a hologram of a Golden Hau in the Great Mine of Onu-Wahi.

It is known that these masks were forged by Artakha, however the method with which he used to do so, is not.

During the Battle of Bara Magna, the Ignika created the Golden Armor, a piece of which was shown to be a golden Hau, but this was not the same mask lost to Tahu, after he transformed into a Toa Nuva. This new golden-colored mask was actually a piece of the Golden Armor, likely containing no additional powers aside from shielding, and the innate capability to activate the armor's special function.

However, when Tahu absorbed the energy of all the existing Kraata in the battle, the armor (including the mask) now housed all 42 of the Rahkshi's powers, effectively turning Tahu into the most powerful Toa alive.

Example Usage
In Comic 4: The Bohrok Awake, all the Toa Mata used their Golden Kanohi's power of Speed, to travel from the Kini-Nui to Ta-Koro in moments.

Great

 * The Toa Mata - Formerly; lost when they became Toa Nuva. Toa_mata_nui_2002.png
 * Tahu - Briefly lost when he was controlled by a Krana; later retrieved
 * Gali
 * Lewa - Briefly lost when he was controlled by a Krana; later regained by Onua.
 * Pohatu
 * Onua
 * Kopaka