TIT
TIT
( 436 )
Its colour is iron-black palling to greyilh andbrownilh-black. It occurs in flattilh angulargrains and fmall lumps. Its internal luftre ismoderately gliftening, between femi-metallicand adamantine. Its fracture is imperfectlyfoliated, palling into fine-grained uneven. Itis opake; is brittle but hard, fo as not to beeaiily pulverizable. Its fp. gr. when in fmallgrams is not readily determined, when in largerpieces it amounts according to Klaproth as highas 4.74.
Some varieties are nearly as magnetic as ironfand; others though not attraCtible by themagnet are yet capable of affedting the polarityof a fufpended magnetic needle; whiie othervarieties have no aftion whatever on the mag-net.
This mineral confilts of oxyd of titaniumcombined with oxyd of iron and a little man-ganefe, but the proportions are liable to muchvariation. The following are the vefults offome of the principal analyfes.
Prom Cornwall Aschaffenburg
Ohlapian
By Klapr.
Klapr.
Klapr.
Vauq.
45.25
22.
84.
49.
5 r -
78.
14.
49.
0.25
O.
2.
2.
3-5
O.
0.
O.
IOO.
IOO
IOO
IOO
.. -
It was firft difcovered by Mr. Gregor mixedwith quartz fand, in the bed of a rivulet in thevalley of Menachan in Cornwall . It has fincebeen found imbedded in quartz near Afchaffen-berg in the Spefl’art foreft; alfo at Bodenmais in Bavaria, at Ohlapian in Hungary in aurifer-ous fand ; in the Uralian mountains in Siberia ,and at Botany Bay in New Holland, &c.
Sp. 5. Iferin.
Its colour is iron-black inclining to brownilh.It occurs in fmall angular grains and in rolledpieces, with a rough ftrongly glimmering fur-face. Internally it is gliftening with a femi-metallic luftre. Its fraCture is more or lefsperfectly conchoidal. It is opake, hard, andbrittle. Sp. gr. 4.5.
Before the blowpipe it melts into a blackifhbrown glafs, which is flightly attracted by themagnet. It is faid to be compofed of,
59.1 Oxyd of Titanium
30.1 Oxyd of Iron
10.2 Oxyd of Uranium
90.4
It has hitherto been found only in the Rie-fengebirge, near the fource of the river Ifer,in granite fand,
§. 2. Atiahfs of Orts.
The analyfis of the ores of titanium, thoughvery fimple, is however very imperfeCt, as weare hitherto almoft entirely unacquainted with
» Klapr. Analyt Iff. Vol. I. p. 49 ^ des Mini
Botany Bay
Uralian Mountains
Chenevix
Lowitz
40.
53-
Oxyd of Titanium
49.
47•
Oxyd of Iron
O.
O.
Oxyd of Manganefe
II.
O.
Silex
IOO
IOO
the compofition either of the falts or oxyds ofthis metal.
The only menftruum of fufficient activityto be employed in the analyfis of thefe ores is-fixed alkali, and this is more efficacious whencarbonated than when eauftic. The methodfollowed both by Klaproth and Vauquelin, inthe analyfis of titanite, is the following.
a. Having ground the ore to a very minutepowder, let it be mixed with five or fix timesits weight of carbonated potaffi, and brought toa ftate of fufion in a crucible. The meltedmafs when poured out will be of a green colourif any iron and manganefe are prefent, butotherwife of a pearl-grey colour. The fufedmafs after being pulverized, is to be digeftedin repeated portions of hot water, till everything foluble is extracted, after which therewill remain a reddiffi white powder, which isnearly pure carbonat of titanium.
b. The alkaline folution contains only a littlefilex and alumine, with the oxyds of manganefeand iron, which are to be feparated in the ufualway.
The calcareo-filiceous titanite was thus ana-lyfed by Klaproth. 6
a. 100 grs. finely pulverized were ignitedfor an hour with four times their weight ofeauftic potaffi, the refulting mafs was foftenedwith water, and digefted with an excefs ofmuriatic acid; the whole was thus diflolvedexcept 12 grs. of filex.
b. The muriatic folution was decompofed by
; i No. jy, p. is, * Analyt. Eff. Vol. 1 . p. 214.