Phillipsite is a mineral series of the
zeolite
Zeolites are a group of several microporous, crystalline aluminosilicate minerals commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminium, oxygen, and have the general formula ・y where is either a meta ...
group; a hydrated
potassium
Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...
,
calcium
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...
and
aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...
silicate, approximating to . The members of the series are phillipsite-K, phillipsite-Na and phillipsite-Ca.
[ The crystals are ]monoclinic
In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in t ...
, but only complex cruciform twins
Twins are two offspring produced by the same pregnancy.MedicineNet > Definition of Twin Last Editorial Review: 19 June 2000 Twins can be either ''monozygotic'' ('identical'), meaning that they develop from one zygote, which splits and forms two e ...
are known, these being exactly like twins of harmotome which also forms a series with phillipsite-Ca.[ Crystals of phillipsite are, however, usually smaller and more transparent and glassy than those of harmotome. Spherical groups with a radially fibrous structure and bristled with crystals on the surface are not uncommon. The ]Mohs hardness
The Mohs scale ( ) of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fair ...
is 4.5, and the specific gravity
Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nea ...
is 2.2. The species was established by Armand Lévy in 1825 and named after William Phillips. French authors use the name Christianite (after Christian VIII of Denmark
Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...
), given by A. Des Cloizeaux in 1847.
Phillipsite is a mineral of secondary origin, and occurs with other zeolites in the amygdaloidal cavities of mafic
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include ...
volcanic rock
Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and me ...
s: for example in the basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...
of the Giants Causeway in County Antrim, and near Melbourne
Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...
in Victoria; and in Lencitite near Rome
Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...
. Small crystals of recent formation have been observed in the masonry of the hot baths at Plombires and Bourbonne-les-Bains, in France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
. Minute spherical aggregates embedded in pelagic red clay were dredged by the Challenger from deep sea sedimentary deposits in the Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
.
It has been discovered that the volcanic ash that Romans employed in the mix for construction of harbor piers and sea walls contained phillipsite, and that an interaction with sea water actually causes crystalline aluminous tobermorite structures in the mortar to expand and strengthen, making the material substantially more durable than modern concrete.''Ancient lessons: Roman concrete durable, green'', Jim Destefani, ed., Ceramic Tech Today, The American Ceramic Society, June 7, 2013
/ref>
See also
*List of minerals
This is a list of minerals which have Wikipedia articles.
Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various ''species''. Within a mineral speci ...
*List of minerals named after people
This is a list of minerals named after people. The chemical composition of the mineral follows the name.
A
* Abelsonite: – American physicist Philip Hauge Abelson (1913–2004)
* Abswurmbachite: – German mineralogist Irmgard Abs-Wurmbac ...
* Roman Concrete
References
*
External links
Structure type PHI
Calcium minerals
Sodium minerals
Potassium minerals
Aluminium minerals
Zeolites
Monoclinic minerals
Minerals in space group 11
{{silicate-mineral-stub