Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: June 3, 2025
There are also other globular masses of the same kind, where the sparry crystallization is either not to be observed, or appears only partially : And now, lastly, In strata of shell-sand, there are found masses of consolidated lime-stone or marble.
It is not possible to crystallise this alkaline salt from a dissolved state, without the combination of that quantity of water, nor to separate that water without destroying its crystalline state. But in this mineral specimen, we have a solid crystalline salt, with a structure which, upon fracture, appears to be sparry and radiated, something resembling that of zeolite.
It is evident from the inspection of this fossil, that the sparry and siliceous substances had been mixed together in a fluid state; and that the crystallization of the sparry substance, which is rhombic, had determined the regular structure of the quartz, at least in some directions.
"In those calcareous strata, which are evidently of marine origin, there are many parts which are of sparry structure that is to say, the original texture of those beds in such places has been dissolved, and a new structure has been assumed which is peculiar to a certain state of the calcareous earth.
The strata of limestone seem to graduate into the slate or schistus strata, between which the calcareous are placed. Fortunately, however, I at last found a fragment in which I thought to perceive the works of organised bodies in a sparry state; I told Mr Clerk so, and our landlord Mr Wright, who had accompanied us.
In examining the tops of granite mountains, or where this rock is exposed to the weather, we may perceive those two species of decay proceeding together. The external surface of the stone, where there is a sufficient mixture of feltspar, is separating into grains which form a species of sand, being nothing but the particles of granite separating by means of the decaying sparry part.
These hard bodies are perfectly united together, in forming the most solid mass; the contiguous parts of some of the rounded fragments are interlaced together, as has already been observed; and there are partial shrinkings of the mass forming veins, traversing several fragments, but perfectly filled with the sparry substance of the mass, and sometimes with parts of the stone distinctly floating in the transparent body of spar.
The mica, with large folia, lies in the direction of the dip of the strata. I found in the primitive limestone a great many crystallized pyrites, and rhomboidal fragments of sparry iron-ore of Isabella yellow.
2dly, In those calcareous strata, which are evidently of marine origin, there are many parts that are of a sparry structure, that is to say, the original texture of those beds, in such places, has been dissolved, and a new structure has been assumed, which is peculiar to a certain state of the calcareous earth.
Now the fact is, that the calcareous body is perfectly inclosed within the solid calcedony, and that they are mutually impressed by each others specific figure, the sparry structure of the calcareous body impressing the calcedony with its type of planes and angles, at the same time that, in other parts, the spherical figures of the calcedony enter the solid body of the spar, and thus impress their mammelated figures into that part which is contiguous.
Word Of The Day
Others Looking