34 
FOSSILIEEROUS HEMATITE NODULES IN LEICESTERSHIRE. 
is of two kinds,—a softisli brown or yellowish material, 
and a compact steel-grey ore taking the usual polish. 3. A 
nearly whole nodule and one of great hardness, which 
exhibits on its weathered surface the fortification type of 
agate,—also indistinct traces of fossils. This is the specimen 
already mentioned as being magnetic at one point only. 4. A 
brown, rather hard, flinty-fractured, siliceous variety of 
the ore, exhibiting, as many of the specimens do when 
polished, grains or little shiny patches of siliceous (?) haematite 
disseminated through the mass. A small hollow in this 
specimen has a coating of mammillated fibrous haematite, 
with a lustre approaching metallic adamantine. 5. A 
very singular, if not unique, form of columnar structure, 
shown in Fig. 9, PI. I. It is of very hard iron-black 
haematite (?) (manganite ?)—streak brownish-red, fracture 
clean to uneven, lustre dull, weathered surface, dark brown 
or like the majority of the nodules. It appears to be a 
fragment of a nodular mass of ore, but what the original 
size may have been is impossible to say. It sliow T s signs 
of having been water-worn to some extent, and subsequently 
fractured at three different times. Upon the original or 
most weathered and water-worn (?) part of the surface no 
signs of columnar structure are seen, but from the different 
fractured faces of the lump it is evident that this structure 
extends in all probability through the whole of it. The 
columns vary between of an inch in width at one end of 
the specimen and at the opposite end, as seen in the 
figure. Some are four-sided, some have more sides, but, 
owing to weathering, the precise forms are not readily dis¬ 
tinguishable. The wavy formation is especially curious. 
This specimen is magnetic and possesses polarity, the poles 
being situated at right angles to the axes of the columns. There 
are no traces of fossils upon it. It takes a good polish, and 
is very heavy. Again, we occasionally find enclosed in 
lumps of the most compact blue ore, small streaks or spots 
of bright red powdery ore. Less often, specimens, when cut 
and polished, exhibit minute branch-like veins of bright 
compact metallic iron running through a body of ore of 
much more earthy character. These may be looked upon as 
veins of “ segregation ” or “ exudation ” in miniature. Very 
rarely nodules are found containing cavities lined with groups 
or bunches of crystals of calcite, &c., one-quarter of an inch 
in lougtli, sometimes encrusted or rendered partially pseudo- 
morphous with a light brown irony mineral. Other hollow 
nodules contain a globular aggregate of soft rounded grains, 
resembling roe, of a brown tint. 
