|Metallic beryllium was first obtained as a dark grey powder by reducing its chloride with potassium. The product of such reduction methods is usually a similar powder, though crystals of the metal sometimes occur. It assumes " a bright grey or white metallic lustre under the burnisher." |
The metal produced by electrolysis is crystalline, with a bright metallic lustre. It crystallises in prismatic and tabular forms of the holohedral division of the hexagonal system, and the density of the crystals is 1.842. This density agrees closely with the 1.85 at 20° C. determined on the metal produced by reduction of the chloride with sodium. Lebeau's electrolytic crystals had a density of 1.73 at 15° C.
The small crystals thus obtained cannot be melted together because a coating of oxide prevents coalescence. To obtain a regulus they are compressed and heated in a non-oxidising atmosphere. The freshly filed metal has a steel-grey colour. Its melting-point is 1280 ± 20° C. (Oesterheld gives 1278 ± 5° C.); it scratches glass, is brittle at ordinary temperatures, ductile at higher, and its specific electrical conductivity is 5.41×104 reciprocal ohms.
Pollok deduced from some of his experiments that beryllium volatilises without fusion under atmospheric pressure. It is said to volatilise readily at 1530° C. under 5 mm. pressure in hydrogen.
Humpidge expressed the relationship between the specific heat and temperature (t) in the formula -
Specific heat = 0.3756+0.00106t – 0.00000114t2.
Its atomic volume has been given as 5.26 and its approximate heat of fusion as 341.
It is probably a " simple element," and its band spectrum resembles that of aluminium.
The stronger lines in the spectrum of beryllium in decreasing order of wave-length (Rowland) are as follows: -
Spark: 4572.9, 3321.5, 3321.2, 3131.2, 3130.6, 2650.7, 2494.7, 2348.7.
Arc: 4572.9, 3321.5, 3321.2, 3131.2, 3130.6, 2650.7, 2494.7, 2348.7.