MINERALOGY OF BLACK LAKE AREA. 
27 
In most of the open pits, joint planes in the massive serpentine are 
seen to be coated in places with a thin deposit of hydromagnesite, in the 
form of stellate groups of acicular crystals. 
STICHTITE. 
The precious serpentine collected at the old Megantic mine, and 
described on page 77, sometimes includes small patches, or is traversed 
by narrow veinlets, of a lilac coloured mineral which has been identified 
as stichtite. Robert Harvie collected the first specimens of stichtite 
that were identified by the authors. 
Occurrence in Tasmania. 
This rare mineral was first found, associated with serpentine, near 
the Adelaide mine at Dundas on the west coast of Tasmania, and up to 
the present time it has not been recorded from any other locality. The 
literature dealing with the mineral has been collected and reprinted in 
a report 1 of the Tasmanian Department of Mines, published in 1914. 
In view of its interest in connexion with the occurrence at the old Me- 
gantic mine, a brief review of the history of the original stichtite is 
given below. 
Petterd describes the mineral as occurring in irregular masses, veins, 
and blebs in a pale yellowish -green serpentine, within which, also, it 
more rarely forms ill-defined bands. At times the serpentine is speckled 
with patches of stichtite, which vary in size from mere spots up to a 
diameter of 10 or 12 mm. The colour is lilac, weathering to brown, and 
the mineral frequently encloses nuclei of chromite. Hardness 1J; 
specific gravity 2 • 20, and also of a purer fragment, 2-12. The structure 
is foliated to compact, or granular. Owing to. the common foliated char- 
acter, the mineral has a chloritic appearance, and was at first referred to 
kammererite, under which name it appeared in the “Catalogue of the 
minerals of Tasmania” in 1896. Later investigations having proved 
that the mineral was a definite new species it was named stichtite , after 
Mr. R. Sticht, the general manager of the Mount Lyell Mining and 
Railway Company, and it is listed under this name in the 1910 catalogue. 
Petterd gives an analysis, made by A. S, Wesley, which is reproduced 
in column (1) (p. 28) ; the analysis leads approximately to the formula 
(CrFe)20* . 6MgO . CO 2 . 13H 2 0. He further states that the mineral 
is soluble with effervescence in hydrochloric acid, yielding a bright 
1 Stichtite, a new Tasmanian mineral, Geological Survey Record No. 2, Dept, of Mines, Tasmania, 
1914. This report contains the following papers: “Description of the mineral," by W. F. Petterd (Catalo- 
gue of the minerals of Tasmania, pp. 167-169, 1910) ; “Note on the optical characters,” by L. K. Ward 
(Ibid, pp. 169-170) ; “Chemical composition," by Laura He*ner (Centralblatt f. Min., etc., No. 18, 1912, 
p. 569); “Physical and optical characters,” by A. Himmelbauer (Tschertn, Min. u. Petr. Mltth., Bd. 
XXXII, Heft 1 u. 2, 1913, p. 135). 
