Diamond Great White

The Imperial Diamond, known also as the Victoria or Great White Diamond probably came from the Jagersfontein mine of the O.F.S. It appeared on the London market in 1884 and had been presumably stolen from the mine. Its original weight was given as 457 carats it was cut into an oval brilliant of 180 carats and a smaller round brilliant of approximately 19-6 carats. The former was purchased by the Nizam of Hyderabad. 

Copper, zinc, and gallium are metals, with properties compatible with these values of the valence. Germanium under ordinary pressure is a metalloid, with the diamond structure and valence 4. At high pressure it is converted into another form, with greatly increased electric conductivity and density corresponding to the white tin structure and valence 2.56. 

Tin is a silvery white metal, with great malleability, permitting it to be hammered into thin sheets, called tin foil. Ordinary white tin, which has metallic properties, slowly changes at temperatures below 18 C to a non-metallic allotropic modification, gray tin, which has the diamond structure. (The physical properties given in Table 18-3 pertain to white tin.) At very low temperatures, around —40°C, the speed of this conversion is sufficiently great that metallic tin objects sometimes fall into a powder of gray tin. This phenomenon has been called the tin pest. ... 

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