Barehills, in a yellowish felspar aventuriné. The crystal is Haüy's Ditétraedre.

CHROME

Is already mentioned among the iron ores. The green oxyde, is also found at the Barehills, colour

ing the talc, as well as the ruby or violet

coloured ore.

The aggregates, including the clays, which form a very large portion of the alluvial soil of the neighbourhood, shall be communicated in a future list, when they shall have been carefully examined.

XXXVII.

Description of some of the combinations of TITANIUM occurring within the UNITED STATES-by the EDITOR.

OF the many new discoveries which have enriched the

science of Mineralogy, none have proved more interesting and worthy of notice, than those which relate to the metals; the number of which has been increased within a few years to an extent not to have been expected, when we consider the few which fell within the observation of the ancient mineralogists. For these we are, in great measure, indebted to the improvements which have taken place in analytical chemistry. To Scheele, and several of the late chemists, and particularly those of the present day, we owe much for our knowledge of the new metals, most of which have been recognized within the United States: and several which are of rare occurrence in the eastern, are found in abundance in the western hemisphere. Among these is Titanium; some of the ores of which, that occur in the United States, it is the object of the present paper to describe. The first discovery of Titanium, is due to an English

mineralogist, the Rev. William Gregor, F. R. S. who in analysing a ferruginous sand from Menachan, in Cornwall, detected a metal differing in properties from any which had been hitherto admitted into that class of mineral bodies. The result of his experiments and observations, he communicated to the public, through Crell's Journal in 1791. Klaproth of Berlin, afterwards in examining the red schorl of Hungary, recognized the presence of the same metal before discovered by Mr. Gregor, since which time Titanium has been found in other mineral bodies.

According to Lampadius,* Titanium in its metallic state, is of a dark copper red colour, and of considerable lustre; is brittle, and when thin, elastic. When exposed to the air, it tarnishes; and when heated, absorbs oxigene. It then becomes blue, it detonates with nitrat of potash; is highly infusible. All the strong acids act upon it with

energy.

It will be unnecessary here to mention the various characters which designate the ores of Titanium. We shall only observe that when the external characters are so indistinctly marked as to admit of a doubt, if a portion of the ore finely powdered be fused with four times its weight of caustic potash, and the fused mass digested several times with water, a whitish powder (oxide of Titanium) will fall to the bottom.

The forms under which Titanium has been found in the United States, are

The Oxide.

The ferruginous Oxide.

The Silico-calcareous Oxide.

* Nicholfon's Journal, vi, 62.

OXIDE OF TITANIUM.

SYNONIMES. Titane oxydé, Haüy. Schorl rouge, Romé de Lisle. Oxide rouge de Titanium, Delametherie. Rutil, Werner. Rutile, Jameson. Titanite, Kirwan. Titane Ruthile, Brogniart.

The specimens described form a part of the writer's Cabinet of the mineral productions of the United States.

No. 1.

Small quadrangular prismatic, nearly acicular semitransparent crystals of the oxide of Titanium, of a dark blood-red colour, variously recumbent on a granitic aggregate of compact felspar, bluish quartz and brown mica.

No. 2.

Small dark red semi-transparent double crystal of the oxide of Titanium, being two four-sided prisms, so connected at their bases, as to form a jointed crystal (Geniculé of Haüy) (P. II, Fig. 1.) the surface highly resplendent, lying on an aggregate of compact felspar, granular carbonate of lime and bluish quartz.

No. 3.

Large amorphous blood-red oxide of Titanium, on white felspar, with dark brown mica and granular carbonate of lime.

No. 4.

Light red acicular oxide of Titanium, imbedded in bluish

quartz, with transparent crystallized felspar, (adularia) and brown mica.

The above specimens, 1, 2, 3, and 4, are from the Island of New-York. They were found in the lime-stone ridge which crosses the Island at its northern extremity, near Kingsbridge. The lime-stone, which is primitive, has running through it in different directions, veins from one to three or four inches thick, composed of quartz, felspar, mica, and granular lime-stone: through which the oxide. of Titanium is sparingly disseminated. The quartz is of the fœtid kind, giving out an unpleasant odour on being fractured.

No. 5.

Amorphous oxide of Titanium of a dark grey red colour, translucent on the edges, having a strong metallic lustre, imbedded in a white fine-grained carbonate of lime.

No. 6.

A detached crystal of oxide of Titanium, in colour similar to No. 5, and in figure resembling No. 2, longitudinally striated.

The specimens 5 and 6 were sometime ago presented to me by Mr. - I regret however, that from an idea of their supposed value, no further information relative to their locality could be obtained, than an assurance that they were found in a marble quarry on the Hudson river.