The hornblende is the characteristic ingredient, and serves to distinguish sienite from granite, with which it has been sometimes confounded; though the felspar, which is generally red, is the more abundant constituent.
It remains to be added that syenitic masses are often very variable as regards their composition; the hornblende is sometimes wanting, in which case we can only recognise an ancient granite.
In other instances the hornblende predominates to such a degree, that a large or small-grained diorite, or greenstone, results.
The granitic rock called Syenite, in which a part of the mica is replaced by hornblende or amphibole, has to all appearance been erupted to the surface subsequently to the granite, and very often alongside of it.
A similar feature is to be observed in another axe of hornblende schist (5 3∕4 inches), and of rather more elongated form than Fig.
The original is of dark green hornblende schist, and was found at Lakenheath, Suffolk.
One formed of hornblende schist, with six strongly projecting circular faces, was found near Ballymena,[2009] co.
Containing hornblendein a scattered state; of or relating to rocks containing disseminated hornblende.
It consists chiefly of orthoclase feldspar with sometimes hornblende and mica.
The failure of the attempts made under the intendant, Don Jose Avalo, must be attributed solely to the ignorance of the persons employed by the Spanish government who mistook mica and hornblende for metallic substances.
Hornblende gneiss from St Sampson and quartz diorite from Capelles, Corvee and elsewhere are transported to England for road metal.
Hornblende and primitive greenstone are found in the vicinity of Adam's Peak and in the Pussellava district.
Alderney consists mainly of hornblende granite and granulite, which are covered on the east by two areas of sandstone which may be of Cambrian age.
Several patches of granite and granulite fringe the western coast, the largest of these is a hornblende granite round Rocquaine Bay.
A crystalline-granular compound of plagioclase and hornblende with magnetite.
Trachyte from Hungary; felsitic paste with crystals of hornblende and sanidine, and a little magnetite.
Spherulitic structure is not infrequent; and occasionally a few crystals of sanidine, augite, or hornblende are to be seen imbedded in the glassy ground-mass.
Rath has recognised the general distinction between them, which consists in the greater abundance of hornblende and mica in the trachyte of the Wolkenburg than in that of the Drachenfels.
In the older rocks, basalt has often undergone decomposition into melaphyre; and amongst the metamorphic rocks it has been changed into diorite or hornblende rock; the augite having been converted into hornblende.
These balls are composed of lamellar feldspar and hornblendeclosely commingled.
On the road to Catia we see the chloritic schist passing into hornblende schist.
Montserrat, a solfatara; fine porphyritic lavas with large crystals of feldspar and hornblende near Galloway, according to Mr. Nugent.
The sea at the foot of Cabo Blanco throws up on the beach rolled fragments of a rock, which is a granular mixture of hornblende and lamellar feldspar.
I observed a fine sienite on several spots; it is of a whitish colour, and contains hornblende and mica in almost equal quantities; granite was also seen, and both rocks probably belong to each other, the presence of hornblende being local.
Farther down sienite was observed, which contained so much hornblende as to change occasionally into hornblende rock, with scattered crystals of quartz.
The bed of the creek was full of blocks of Sienite, of hornblende Porphyry, of greenish Pegmatite, and of cellular Basalt.
I observed Pegmatite of a white colour, and hornblende Porphyry and Diorite.
I observed a sienite, to which the distribution of the hornblende in layers had given the stratified appearance of gneiss.
A dark green hornblende schist occurs at two miles before coming to Shabushquaia river.
Mica and hornblende contain considerable oxide of iron, while feldspar has none.
When mica and hornblende are ground up, the result is blue or red clays, as the oxidation of the iron turns the clay red; while the clay made of feldspar is light yellow or white.
Mica andhornblende generally contain considerable oxide of iron, while feldspar usually yields only a trace or none.
Therefore clays which are derived from feldspar are light-colored or white, while those partially made up of decomposed mica or hornblende are dark, either bluish or red.
Not unfrequently quartz and hornblende are arranged in layers in almost amorphous feldspar.
The surface of the country is in general good strong clay; all the rocks are of gneiss and granite, in the composition of which hornblende predominates.
The difference in form of the two substances may be explained by the different circumstances under which they have been produced, the form of hornblendebeing the result of slower cooling.
Crystals of augite have been met with in the scoriae of furnaces, but never those of hornblende; and crystals of augite have been obtained by melting hornblende in a platina crucible; but hornblende itself has not been formed artificially.
A variety of trap, composed of hornblende and felspar.
If hornblende is the most abundant mineral, the same scaly structure shows in a dark rock calledhornblende schist, rich in iron.
The hornblende rusts away chiefly under the influence of moist air and trickling water.
The fine mud which now appears as beds of slate was the decay of feldspar andhornblende in the same granite.
Hornblende is a dark mineral which contains considerable iron.
Hornblende is made of silicon, oxygen, carbon, and iron.
A little hornblende was present, but scarcely a trace of mica.
The siliceous matter of the shales has become quartz rock, which sometimes contains hornblende and mica, and therefore constitutes a kind of granite.
When hornblende takes the place of mica, it is syenite.
When any of these minerals becomes so abundant as to constitute a considerable part of the mass, the rock becomes talcose, micaceous, or hornblende slate.
Hornblende schist is common over large areas in the Lake Superior region.
The bones were dug up by Mr. Walter Mantell from a bed of marly sand, containing magnetic iron, crystals of hornblende and augite, and the detritus of augitic rocks and earthy volcanic tuff.
Hornblende when primary is often brown, and may surround augite or be perthitically intergrown with it; original green hornblende probably occurs also, though it is more frequently secondary.
In some gabbros and norites reaction rims of fibrous hornblende are found around both hypersthene and diallage where these are in contact with felspar.
The primitive sienites and hornblende rock of the sources of the St. Francis and Grand rivers, support it.
At a place called the Narrows, the river rushes between alpine peaks of sienite and black hornblende rock, which lies in huge and confused heaps, plainly indicating ancient volcanic action.
The only rock which I observed there possessing any appearance of stratification seems to consist of mica, hornblende and a little felspar, in a state of intimate mixture.
Lastly, Gustavus Rose fused a mass ofhornblende in a porcelain furnace, and found that it did not, on cooling, assume its previous shape, but invariably took that of augite.
In some places the siliceous matter of the schist becomes a granular quartz; and whenhornblende and mica are added, the altered rock loses its stratification, and passes into a kind of granite.
Dolerite and diorite; components, hornblende and felspar, or augite and felspar in grains.
When hornblende is the substitute for mica, which is very commonly the case, the rock becomes Syenite: so called from the celebrated ancient quarries of Syene in Egypt.
The same mineralogist observed certain crystals in rocks from Siberia which presented a hornblende cleavage, while they had the external form of augite.
There is no doubt that many of the fine-grained and dark-coloured trap rocks, called basalt, contained hornblendein the place of augite; but this will be deemed of small importance after the remarks above made.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "hornblende" in a variety of sentences. We hope that you will now be able to make sentences using this word.
