The history of this mineral begins long ago in ancient times… According to some sources it was discovered by the Romans, and according to other, quartz porphyry deposits were discovered at the instigation of Cleopatra. In any case, nowadays one can see various statues and vases, interior items and sarcophagi made of this stone in well-known museums of Europe, at the World London exhibition, in Vienna, Paris and other cities.
Structure of quartz porphyry
Quartz porphyry is also called rhyolite. This mineral is formed when magma rich in silicic acid rises. Since magma is highly mobile, quartz porphyry lies in the form of massive cover outpourings. It has a fine-grained structure comprising quartz impregnations (about 20%, and rhyolites can be quartz-free), potassium-sodium feldspar (from 40% to 90%), and sometimes impregnations of oligoclase, orthoclase, pyroxene, biotite and plagioclase (10 -60%). Quartz porphyry is a fine-grained rock, by its chemical composition close to granite.
Color of quartz porphyry
In nature, the samples of quartz porphyry with intense color are extremely rare, but after treatment (grinding and polishing) this stone acquires a luxurious look. The term “porphyry” is derived from Greek porphэreos and means “dark red”, “purple”. The stone was given such a name due to the color peculiarities of rhyolite: traditionally it has brown and red-brown color. Red shades appear due to iron and feldspar impurities, and quartz elements impart grayish tone. Quartz porphyry visually seems motley.
Properties of quartz porphyry
Compared with granite, quartz porphyry has greater strength. Another characteristic feature of this mineral is self-cleaning ability: for example, if the surface gets greasy or oily stain, then eventually it will disappear. The structure of the stone is porous, that’s why it is characterized by high moisture absorption. Quartz porphyry is resistant to freezing temperatures, and highly resistance to various reagents. The stone is resistant to wearing, scratches and bumps.
The use of quartz porphyry
All these properties provided the usage of quartz porphyry in paving sidewalks and borders in Italy, in the XIX-XX centuries. Nevertheless this stone is mostly used to create unique interiors. In interior furnishing it can be seen in the mantelpieces; countertops and decorative elements made of it are luxury and exquisite. Quartz porphyry looks perfectly with bleached walls, decorative plaster, wood beams. Ceilings with thinly sliced sheets of quartz porphyry are unique projects. This stone is used in projects that require high quality of interior decoration with complex architecture.
It is also used for external decoration of facades, plinths, terraces and patios. The stone with a rough surface is perfect for facing swimming pools, decking curbs and paving different coverings for sloped surfaces. In landscape design quartz porphyry is used to create rock gardens, rockeries, and for the decoration of waterfalls and cascades. Directly in the construction the application of the rhyolite is very rare due to the limited availability and difficulty in treatment of this material.
As a rule, quartz porphyry is used both with treated and with a natural surface. Common formats of this stone are various plates, tiles and bars of different thicknesses. The plates of wrong size, with ragged or cut edges are used in the creation of mosaics of natural stone.