Marcasite Sentence Examples
Marcasite is thus the less stable of the two modifications of iron disulphide.
The crystals are orthorhombic, with angles similar to those of marcasite; they are often prismatic in habit, and the prism M is usually terminated by the deeply striated faces of an obtuse dome r.
Twinning is not uncommon, the twinplanes M (i io) and g (roi) being the same as in marcasite.
Other species belonging to this isomorphous group of orthorhombic minerals are marcasite (FeS2), lollingite (FeAs 2), safflorite (CoAs2) and rammelsbergite (NiAs 2).
Apart from crystalline form, the external characters of marcasite are very similar to those of pyrites, and when distinct crystals are not available the two species cannot always be easily distinguished.Advertisement
The colour is usually pale bronze-yellow, often rather lighter than that of pyrites; on freshly fractured surfaces of pure marcasite the colour is tin-white, but this rapidly tarnishes on exposure to air.
Arsenical varieties of marcasite, containing up to 5% of arsenic, are known as lonchidite and kyrosite.
Marcasite readily oxidizes on exposure to moist air, with the production of sulphuric acid and a white fibrous efflorescence of ferrous sulphate, and in course of time specimens in collections often became completely disintegrated.
Many experiments have been made with a view to determining the difference in chemical constitution of marcasite and pyrites, but with no very definite results.
It is a noteworthy fact that whilst pyrites has been prepared artificially, marcasite has not.Advertisement
Marcasite occurs under the same conditions as pyrites, but is much less common.
Whilst pyrites is found abundantly in the older crystalline rocks and slates, marcasite is more abundant in clays, and has often been formed as a concretion around organic remains.
In the Chalk of the south-east of England nodules of marcasite with a fibrous radiated structure are abundant, and in the Chalk Marl between Dover and Folkestone fine twinned groups of "spear pyrites" are common.
Iron-pyrites was formerly called marcasite, a word variously written marcasin, marchasite, marchesite, marquesite, &c. The two names are now applied to distinct mineral species.
Its hardness is about 6, and its specific gravity 4 9 to 5.2, being rather more than that of marcasite.Advertisement
Contrary, too, to popular belief, he has found a fibrous structure more common in pyrite than in marcasite.
In coal it not infrequently forms bands and nodules known as "brasses," and may also be finely disseminated through the coal as "black pyrites"; but much of the so-called pyrites of coal is really marcasite.
A similar action probably explains the origin of pyrites and marcasite in coal and lignite, in clay and shales, and in limestone like chalk.
Iron disulphide, FeS2, constitutes the minerals pyrite and marcasite; copper pyrites is (Cu, Fe)S2.
It occurs in nature as the mineral melanterite, either crystalline or fibrous, but usually massive; it appears to have been formed by the oxidation of pyrite or marcasite.Advertisement
Bouquets of flowers and tendrils in silver marcasite, catching the light in elegant sparkles.
Judith and Jack quickly noticed that out of all the pieces they sold, nothing went quicker than the jewelry containing vintage marcasite.
Since their supplies were necessarily limited, the two decided to begin designing and producing their own marcasite jewelry, combining traditional vintage styles with fresh fashion trends.
The bracelet itself is a 7.25 inch long strand of sterling silver marcasite links with a standard clasp, but as always with charm bracelets, it's the charms themselves that garner all the attention.
Since Judith Jack works almost exclusively with sterling silver and marcasite, it's good to know a little about these metals and how to care for them.Advertisement
Marcasite is the modern name for a mineral we once called "Fool's Gold".
Marcasite is actually iron pyrite, and it has been used to create jewelry for thousands of years.
Marcasite and sterling silver charms and jewelry require extra care to preserve their finish and luster.
Bella's Twilight engagement ring made from cubic zirconia, sterling silver and marcasite is a popular item for engagement and promise rings among Twilight fans.
The cubic zirconia, sterling silver and marcasite version of Bella's engagement ring is a beautiful but affordable reproduction of the Twilight engagement ring.
Bella's Twilight engagement ring made from cubic zirconia, sterling silver and Marcasite is a popular fashion version of the Twilight engagement ring.
The CZ, sterling silver and marcasite is one of the many variations of the Twilight engagement ring.
Bella's engagement ring made from CZ and marcasite stones set in a sterling silver band is a lovely version that presents as well as CZ and white gold rings.
Combining CZ and marcasite creates a beautiful antique elegance.
It is difficult to find Bella's Twilight engagement ring made from cubic zirconia, sterling silver and marcasite cubic zirconia.
Some jewelry artists who make Twilight inspired rings may be willing to do a custom order incorporating marcasite.
A CZ, marcasite and sterling silver version of Bella's ring may be in the right price range for young couples who want a promise ring or a pre-engagement ring.
The compound FeS 2 is dimorphous, and the modern practice is to distinguish the cubic forms as pyrites and the orthorhombic as marcasite (q.v.).
Moreover, the colour of pyrites is pale brass-yellow, whilst that of marcasite when untarnished may be almost tin-white.