It appears to be a decomposed trachyte, in which the feldspar has been affected, but not the mica.    From Wordnik.com.  [The South of France—East Half] Reference

Jasper abounds in the trachyte and dolomite, and large blocks, of beautiful variety, are found in some districts.    From Wordnik.com.  [Rambles in the Islands of Corsica and Sardinia with Notices of their History, Antiquities, and Present Condition.] Reference

About 55 statues are made of other stone – red scoria, basalt, or trachyte – and are smaller than the average size of 5 m.    From Wordnik.com.  [The Eight Wonder of the World – Easter Island | Impact Lab] Reference

He decided that the mass of trachyte forming the Puy-de-Dôme was simply granite which had been softened and pushed up as a protuberance.    From Wordnik.com.  [Dictionary of the History of Ideas] Reference

The bedded volcanic rocks which form a series of ridges trending north-west comprise porphyritic basalts, andesite, and, near Port Luchdach, brownish trachyte.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 4, Part 4 "Bulgaria" to "Calgary"] Reference

Puy de Dôme, with its cone of trachyte and its strata of basaltic lava, induced him to abandon as untenable the doctrines of Werner on the formation of these rocks.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3 "Brescia" to "Bulgaria"] Reference

Epidaurus, on the same spot where Russegger has found veins of trachyte.    From Wordnik.com.  [COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1] Reference

At the bottom are seen great cliffs of massive trachyte (Number 1 in section).    From Wordnik.com.  [The Naturalist in Nicaragua] Reference

The prevalence of trachyte shows that the products have cooled under feeble pressure.    From Wordnik.com.  [The Andes and the Amazon Across the Continent of South America] Reference

He brought with him a hard white stone much resembling trachyte, and fragments of fine green jasper.    From Wordnik.com.  [The Land of Midian — Volume 2] Reference

Granite and mica slate are shaken as well as limestone and sandstone, or as trachyte and amygdaloid.    From Wordnik.com.  [COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1] Reference

Pumice and trachyte are the most common rocks around this mountain, and these are augitic or porphyroid.    From Wordnik.com.  [The Andes and the Amazon Across the Continent of South America] Reference

On the summits of the hills the granite has a rough trachytic appearance, but does not pass into true trachyte.    From Wordnik.com.  [The Voyage of the Vega round Asia and Europe, Volume I and Volume II] Reference

The trachyte which once formed the summit of this mountain is now spread in fragments over the plain of Riobamba.    From Wordnik.com.  [The Andes and the Amazon Across the Continent of South America] Reference

Or, again, I see no difficulty in a mass of trachyte being exposed by subsequent dislocations and bared or cleaned by rain.    From Wordnik.com.  [More Letters of Charles Darwin — Volume 2] Reference

"It is a polygonous pyramid of dark trachyte, with gray cupulas on jutting walls and projecting cornices, a forest of pinnacles.".    From Wordnik.com.  [Flash-lights from the Seven Seas] Reference

The abyss is girt with a ragged wall of dark trachyte, which rises on the inside at various angles between 45° and perpendicularity.    From Wordnik.com.  [The Andes and the Amazon Across the Continent of South America] Reference

Built upon a small hill from blocks of trachyte, it consists of twelve terraces rising one above another, and connected by staircases.    From Wordnik.com.  [Through Central Borneo; an Account of Two Years' Travel in the Land of Head-Hunters Between the Years 1913 and 1917] Reference

The word Naverachic is of Tarahumare origin; navé means "move," and ráchi refers to the disintegrated trachyte formation in the caves.    From Wordnik.com.  [Unknown Mexico, Volume 1 (of 2) A Record of Five Years' Exploration Among the Tribes of the Western Sierra Madre; In the Tierra Caliente of Tepic and Jalisco; and Among the Tarascos of Michoacan] Reference

As has been shown, the beautiful trachyte of Mitla, which, whilst it is tough and enduring, is soft, and lends itself readily to the chisel.    From Wordnik.com.  [Mexico Its Ancient and Modern Civilisation, History, Political Conditions, Topography, Natural Resources, Industries and General Development] Reference

It was perched on a promontory of heliotrope-tinted trachyte; struck by the morning beams it flashed and glowed like a jewel in the sunshine.    From Wordnik.com.  [South Wind] Reference

The existence even of trachyte has not yet been verified in the Sierra Nevada de Merida which links the Andes and the littoral chain of Venezuela.    From Wordnik.com.  [Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 3] Reference

The angular blocks of trachyte imbedded in the stratum Number 5 in section are exactly the same in composition as the great bed below, and in them.    From Wordnik.com.  [The Naturalist in Nicaragua] Reference

The solid products of Pichincha since the Conquest have been chiefly pumice, coarse-grained and granular trachyte, and reddish porphyroid trachyte.    From Wordnik.com.  [The Andes and the Amazon Across the Continent of South America] Reference

It is composed of fine tufa, in which is imbedded a great number of large angular fragments of trachyte, some of which are more than three feet in diameter.    From Wordnik.com.  [The Naturalist in Nicaragua] Reference

Just opposite the house the Juigalpa river, which comes flowing down over a flat bed of trachyte, leaps down a deep narrow chasm that it has cut in the hard rock.    From Wordnik.com.  [The Naturalist in Nicaragua] Reference

In that part of the Andes with which I am best acquainted, between 8 degrees south latitude and 21 degrees north latitude, all the colossal summits are of trachyte.    From Wordnik.com.  [Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 3] Reference

But we see no reason why they could not be the upper portion of the solid trachyte cone blown into the air at the great eruption which cleared out this enormous crater.    From Wordnik.com.  [The Andes and the Amazon Across the Continent of South America] Reference

But at a later period a wide chasm formed diagonally from south-west to north-east, through which was gradually forced out the trachyte which was to form a mountain chain.    From Wordnik.com.  [A Journey to the Interior of the Earth] Reference

All were made out of very hard, tough trachyte; and the labour required to make the principal one out of such difficult material without tools of iron must have been immense.    From Wordnik.com.  [The Naturalist in Nicaragua] Reference

Often, where the water flows over beds of dark grey basalt, masses of trachyte, closely resembling syenite, have formed "potholes," and by mutual action have been worn to pebbles.    From Wordnik.com.  [The Hawaiian Archipelago] Reference