The Constituents of Banded Humic Coal. 171 
LITHOLOGICAL INGREDIENTS IN BRITISH HUMIC GOALS. 
British Terms. 
Vi train. 
| Clarain. 
Durain . 
Fusain. 
Popular terms 
bright, glance or glanze coal ; 
softs ; ‘ dice ’ (Some bright 
clarains contain 90% or more 
vitrain : some dull clarains 
contains a large proportion of 
durain) . 
hards ; 
bone 
mother of 
coal ; 
‘ mineral ’ 
charcoal 
German terms 
Glanzkohle (bright coal) ; 
‘ structureless ’ — 
euvitrit ; 
with structure — 
provitrit 
Mattkohle (dull 
coal) ; (includes 
some clarains 
with dissem- 
inated durain 
wdiich cannot be 
placed in vitrits); 
Faserkohle 
(fibrous coal) 
soft — Staub- 
faserkohle ; 
hard — 
Hartfaserkohle ; 
vit 
rit 
durit 
fusit 
Thiessen’s 
terms 
anthraxylon 
(often definite 
fragments of 
wood or 
periterm) 
attritus ( 
miscellane 
generally 
ous tissues) 
anthraxylon 
(definite 
woody 
fragments) 
Average % in 
British seams 
1 — 20 
30—99 
1—50 ; 
very variable, 
1 — 10 ; 
av. 2-5 
Physical 
properties 
bright, glassy, 
not streaked ; 
homogeneous 
to the naked 
eye 
bright and 
silky, but not 
glassy ; 
streaked 
granular ; hard ; 
compact ; 
dull black ; 
heavy 
soft ; black ; 
charcoal -like ; 
soils the 
fingers 
Extent of 
lenticles 
(a) vertical 
(h ) lateral 
seldom more 
than in. 
usually small 
1/16 to 3 ins. 
often great 
^ to 4 ins. 
often great 
usually 
1/1.6 to ^ in., 
but up to 1 in. 
usually a few 
inches 
Fractured 
surface 
conchoidal 
straight 
irregular ; 
granulated 
irregular ; 
powdery ; 
Contact surface 
with other 
ingredients 
well defined 
not well 
defined 
(see durain) 
not well 
defined : 
interlocks, 
chiefly with 
clarain 
well defined 
General 
chemical 
composition 
high in 
hydrocarbons 
and in ulmins 
high in 
hydrocarbons 
and in ulmins 
next to fusain 
in % of car- 
bon ; high in 
‘ resins ’ 
% of carbon 
high ; % of 
oxygen and 
hydrocarbons 
low 
Moisture 
present 
high 
{e.g. 9 - 9 %) 
fairly high 
\e.g. 8-6%) 
fairly low 
{e.g. 6-o%) 
low 
'(t.e. 3-1%) 
I 933 August 1 
