 | Parker Cleaveland - Geology - 1816 - 702 pages
...passage of water. Sometimes, indeed, this rock is vesicular. Some varieties are sufficiently solid to give fire with steel, while others are friable, and may be reduced to powder even bv the fingers; but this powder discovers the hardness of quart/, by the ease, with which it scratches... | |
 | Parker Cleaveland - Geology - 1822 - 886 pages
...passage of water. Sometimes, indeed, this ruck is vesicular. Some varieties are sufficiently solid to give fire with steel, while others are friable, and may be reduced to powder even by the fingers ; but this powder discovers the hardness of quartz by the ease, with which it scratches glass or steel.... | |
 | Encyclopaedia Americana - 1832 - 620 pages
...admit the passage of water. Sometimes, indeed, this rock is vesicular. Some varieties are so solid as to give fire with steel, while others are friable, and may be reduced to powder even by the fingers. Its fracture is always granular or earthy, although it may be at the same time conchoidal or splintery.... | |
 | Francis Lieber, Edward Wigglesworth - Encyclopedias and dictionaries - 1835 - 624 pages
...admit the passage of water. Sometimes, indeed, this rock is vesicular. Some varieties are so solid as to give fire with steel, while others are friable, and may be reduced to powder even by the fingers. Its fracture is always granular or earthy, although it may be at the same time conchoidal or splintery.... | |
 | Edward Shaw - Masonry - 1846 - 342 pages
...distinguishable by the naked eye, and sometimes their magnitude is equal to that of a nut or an egg. The cement is variable in quantity, and may be calcareous...structure, arising from scattered plates of mica, and hare been called sandstone slate. Its most common color is gray or grayish ; it is sometimes reddish,... | |
 | Francis Lieber - Encyclopedias and dictionaries - 1851 - 618 pages
...admit the passage of water. Sometimes, indeed, this rock is vesicular. Some varieties are so solid as to give fire with steel, while others are friable, and may be reduced to powder even by the fingers. Its fracture is always granular or earthy, although it may be at the same time conchoidal or splintery.... | |
 | Francis Lieber, Edward Wigglesworth, Henry Vethake - Encyclopedias and dictionaries - 1851 - 624 pages
...admit the passage of water. Sometimes, indeed, this rock is vesicular. Some varieties are so solid as to give fire with steel, while others are friable, and may be reduced to powder even by the fingers. Its fracture is always granular or earthy, although it may he at the same time conchoidal or splintery.... | |
 | G.P. Putnam & Co - 1852 - 728 pages
...even silicious. \Vhen silicious, sandstone resembles quartz. Some varieties are so hard as to (rive fire with steel, while others are friable, and may be reduced to powder by the fingen. Some have a slaty struoturc, arising from scattered and insulated plates of mica, and... | |
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... or even siliceous. When siliceous, the mineral often much resembles quartz. The texture of some sandstones is very close, while that of others is so loose and porous as to admit the passage of water. Sometimes, indeed, this rock is vesicular. Some... 