AN ANODIZED STEEL AND BLACK DIAMOND SET DUAL TIME ZONE SQUARE WRISTWATCH WITH OVERSIZED DATE, de Grisogono, 'INSTRUMENTO NO. UNO', CIRCA 2000

anodized steel jeweled lever movement, matte black dial with eccentric dials for dual time zone display, one with applied Arabic numerals and the other with baton numerals, twin apertures for oversized date display, square curved case with H-shaped lugs accented with 14 circular-cut black diamonds, black diamond-set crown, water-resistant type glazed display back secured by four screws, case, dial and movement signed, with an anodized steel de Grisogono double deployant clasp. 

This 'No. Uno' wristwatch embodies the spirit of luxury house de Grisogono, owned by Fawaz Gruosi who is considered an authority on the black diamond.  The 'Spirit of de Grisogono' is reputed to be the world's largest cut black diamond weighing an impressive 312.24 carats and the 5th largest diamond in the world.