In our store we usually do not make polished (bright) finishes. We do not bathe the pieces either and therefore our gray gold does not have the white color that other jewelers get bathing with another metal such as the Rhodium.
They would …
GRUP1 Metals Purses like the Thousands of thousand (24kt)
GRUP2 The foundational alloys workshop like Plati 950, Gold 750 (18kt) in its various colors red, yellow, green and gray and finally silver. The finishes are percusio, matizado or eroded.
GROUP 2 Those of high hardness such as the Inox and the Titanium
Group 4 Metals of little use, due to the difficulty of working them, but suitable for jewelry such as Paladi or Tantal.