Properties
It is a very dense mineral-like substance of the nature of coal that does not demonstrate crystallinity. It generally comes in black, but can also be velvet-black, blackish brown, grey or greenish.
Oltu stone's most interesting characteristic is its softness when excavated. It only begins to harden when exposed to the air. For this reason, it can be carved very easily.
It attracts, by way of static electricity, light substances like dust when rubbed. Oltu stone burns bursting in flames, and leaves ash behind.
To distinguish true Oltu stone from the artificial jet, it is rubbed against unglazed porcelain. Real Oltu stone will leave a chocolate brown streak. The structure of Oltu stone, which is remarkably like the wood, can be seen under magnification.
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Famous quotes containing the word properties:
“The reason why men enter into society, is the preservation of their property; and the end why they choose and authorize a legislative, is, that there may be laws made, and rules set, as guards and fences to the properties of all the members of the society: to limit the power, and moderate the dominion, of every part and member of the society.”
—John Locke (1632–1704)
“A drop of water has the properties of the sea, but cannot exhibit a storm. There is beauty of a concert, as well as of a flute; strength of a host, as well as of a hero.”
—Ralph Waldo Emerson (1803–1882)