370 The N.Z. Journal of Science and Technology. [Nov. 
After calcination Nos. 5 to 9 would have the following compositions 
■ 
— 
5. 
6. 
7. 
8. 
9. 
Silica 
18-31 
27-15 
28-18 
5-63 
2-59 
Alumina 
0-84 
0-30 
0-29 
0-58 
1-43 
Iron oxide 
12-81 
12-09 
10-14 
15-59 
19-53 
Lime 
52-23 
42-72 
43-05 
60-10 
56-28 
Magnesia 
15-42 
17-22 
18-16 
17-84 
19-34 
Undetermined 
0-39 
0-52 
0-18 
0-26 
0-83 
100-00 
100-00 
100-00 
100-00 
100-00 
(1.) Geol. Surv. Bull. No. 3, p. 38. 
(2-4.) Samples forwarded by Mr. F. G. Gibbs. 
(5-9.) Samples forwarded by Mr. J. Bassett. 
Analyses made in Dominion Laboratory (J. S. Maclaurin, Dominion Analyst). 
It will be observed that none of the samples analysed contains sufficient 
magnesia to be called a dolomite. The presence of from 5-36 to 11-32 per 
cent, of iron oxide, reported as Fe 2 0 3 , but partly in the form of carbonate, 
should be noted. Most of the samples are far too siliceous to be of any 
value as furnace-linings. The rock represented by analysis No. 3 is an 
altered ultra-basic composed of magnesite and serpentine. It is understood 
that all the samples represented by analyses Nos. 2 to 9 came from out¬ 
crops on the Parapara River near Richmond Flat. 
The occurrence of fairly pure dolomite near the old Collingwood Coal¬ 
mine, less than two miles from Collingwood, is of such possible importance 
that all the particulars available will be given. 
The earliest reference to dolomite in this locality is contained in the 
Eighth Annual Report of the Colonial Museum and Laboratory, 1873, page 16. 
Skey’s analysis and remarks may be quoted in full:— 
“ No. 1417 is a new rock to New Zealand—dolomite. It occurs at 
Collingwood, Nelson, in a massive form. 
L ‘ This mineral is largely used for manufacturing Epsom salts (sulphate 
of magnesia). 
“ The annexed results of its analysis show it to be a true dolomite, 
and very pure, being composed of single equivalents of the carbonates 
of lime and magnesia, with but a small quantity of iron oxides and 
silicates .J 
“ Carbonate of lime .. .. .. .. 53-51 
Carbonate of magnesia .. .. .. .. 42-61 
Iron oxides . . .. .. .. .. 1-31 
Silica .. .. .. .. .. .. 1-03 
Water . . .. .. .. .. .. 0-51 
98-97 ” 
In the next annual report (9th, 1874, pp. 17-18) Skey writes,— 
“ j Dolomite .—This interesting mineral was announced in the last annual 
report as occurring on the ground of the Collingwood Coal Mining Company, 
and the exact composition of the single specimen furnished at the time was 
stated there. Other specimens have now been obtained by the [Geological] 
Survey, which are equally as good, and it has been ascertained that the 
mineral occurs in a bed of considerable thickness.” 
