THE CRANBOURNE METEORITES 
31 
Iron-nickel Phosphides 
Four varieties of iron-nickel phosphides have been observed in 
the meteorites. In appearance, etching behaviour, and manner 
of occurrence, these varieties are identical with those found in 
the Pakenham meteorite, and figured in its description (Edwards 
and Baker, 1941). 
Two of them, schreibersite and a yellow unidentified phosphide, 
occur associated together, forming rims around the sulphide 
nodules, the schreibersite being much the more abundant. They 
are not found away from the nodules. The others, rhabdite and 
schreibersite-B, occur in the nickel-iron and do not appear in the 
nodules. 
The schreibersite is a tin-white, brittle, hard mineral that 
cannot be scratched with a steel needle, occurring as the outer rim 
of the nodules (Plate IV, Fig. 4). It is difficult to polish on 
account of its brittleness, is distinctly anisotropic and strongly 
magnetic. On treatment with nitric acid it effervesces very slowly, 
the bubbles rising from the numerous cracks in the surface. With 
potassium hydroxide it very slowly develops a brown stain that 
washes brown and rubs pale brown. The action may take several 
minutes to develop, and sometimes appears only after several 
applications of the reagent. This is presumably due to the diffi- 
culty of removing films of oil from the surface, the oil having 
entered the many cracks during polishing. 
The yellow phosphide has a creamy-yellow colour and is readily 
scratched with a needle. It is isotropic and does not appear to be 
magnetic. It is negative to all etching reagents other than 
mercuric chloride, which slowly stains it a purplish brown. The 
stain washes the same colour and is difficult to rub off, when it 
leaves a roughened surface. 
Rhabdite occurs as small rhombs and prisms disseminated 
through the massive kamacite. It is much harder than the enclos- 
ing iron, and cannot be scratched with a steel needle. It is brittle, 
brown by contrast with the iron, distinctly anisotropic and strongly 
magnetic. It is negative to all standard etching reagents. 
Schreibersite-B occurs as occasional large irregular areas, the 
shapes of which are partly controlled by the octahedral structure 
of the iron, but chiefly as fine vein-like areas in the interstices of 
the a-nickel-iron crystals. It is extremely difficult to polish on 
account of its brittleness and hardness. It is weakly anisotropic 
and generally resembles the schreibersite in appearance, but its 
colour is almost identical with that of the rhabdite crystals in the 
adjacent iron crystals. Its behaviour with etching reagents 
