Home » Blog » Interiors Design ideas » Portoro Marble: the Italian black and gold natural stone
Contents
Portoro Marble, also known as black and gold marble, is a fine variety of Italian marble from the charming Golf of Poets, in the Ligurian province of La Spezia. It is one of the most beautiful among the polychromatic marbles. This precious Italian stone consists an intense and bright black colour with gold veins running through it that range from intense yellow to honey colour.
The peculiarity of its appearance makes it a unique marble, irreplaceable as an ornamental stone. There is no stone similar, in luxurious sophistication or characteristic, to this black and gold beauty. Portoro is a natural work of art, in front of which it is easy to become enchanted.
The geological composition of Portoro is calcareous with a microcrystalline structure. Marine substances are responsible for the dark colour and also the golden veins, which are a product of the organic marine materials oxidising. The microcrystalline structure contributes to the particularity of the Portoro and also renders the stone more compact.
The deep and intense black colour of this marble gives the appearance of an almost velvety texture, which is particularly observable when the slabs are polished. These polished slabs look as if gold has been poured directly onto the stone. The veins, streaks, spots and shadows of this black and gold marble are the result of pyrite and ocher-limonite substances.
Portoro is commercially considered suitable for many different uses: for artistic application, columns, church and palace interiors, cladding, flooring and furniture tops. The polished finish is preferred as it adds a level of elegance. This black and gold marble, given its unique veins and high cost, is often used in luxury residences, prestigious hotels and affluent villas. Portoro is frequently used as an inlay, as it creates a perfect contrast when combined with a light coloured marble.
Based on the intensity of the colours, both the dark background and the veins, Portoro marble has several variations in quality. Starting from the top and working our way down, we can distinguish five different types or levels of quality:
The most precious variety are the typology in which the yellow veins are more present. The other varieties, with veins and spots that are nearly white, are also widely requested due to, despite being less valuable, their superior resistance.
Theoutcrops ofPortoro, which are used for extraction, are present exclusively in the La Spezia province, extending from the Tinetto, Palmaria and Tino islands towards Portovenere. The landscape and environment of these beautiful places are delicate, therefore the cultivation of the quarries is carried out with particular attention.
The current number of quarries is very limited in comparison to the last century, the blocks are extracted from large chambers whose vaults are supported by pillars to avoid any impact on the landscape. On the Istituto Luce website there is a short video showing the mining of Portoro quarries back in 1932.
Other outcrops of Portoro are also resent in Tuscany, in the Apuan Alps and Umbria, although they do not present the characteristic features of the Portoro extracted in Liguria.
We do not know the exact starting date of the exploitation of the Portoro marble deposits, we presume that the quarrying for this black and gold marble was already taking place during Roman times. Initially, small blocks of stone were detached to be used, mainly, in the construction of houses, then gradually Portoro was exploited for more purposes. Buildings adorned in Portoro became more prominent.
The first uses of Portoro marble date back to the Roman Imperial villas, and probably to the temple of Venus which overlooks the Gulf of La Spezia, above which the church of San Pietro was built. Even in the ancient Roman colony of Luni, which extended into territories of La Spezia which still exist today, there is evidence of Portoro having been used in the perimeter walls of the amphitheatre.
During the reign of Cosimo I de’ Medici there was a great push for the research and extraction of polychrome marbles such as Giallo Siena, Brecce Medicee and Portoro. Various examples could be found in Italy and Europe, even in the Baroque period. In Rome it was used inside several churches such as, San Pietro in Vincoli, San Silvestro in Capite, San Paolo, San Giovanni in Laterano and San Lorenzo.
At the beginning of the 19th century, exports to Europe began, firstly to France, Belgium and Switzerland to adorn their castles and palaces such as Versailles, Marly and Compiegne. Later on exports to the United States of America began: the large projection room of Paramount Studios is coated with this beautiful ‘black and gold marble’.
Credits of some pictures: James St. John, Roll Stone e Vengomatto, from Flickr and Wikipedia, shared with licenses CC BY 2.0, CC BY-SA 2.0 e CC BY-SA 3.0
When you think of Carrara, your mind immediately goes to the Carrara marble quarry.Carrara marble quarries are huge white wounds that open along the sides of the Apuan Alps: a fascinating orograph[...]
Alabaster stone is an evaporitic sedimentary rock of chalky or calcitic origin. The name probably has oriental origins; the Ancient Greeks called alábastron a vase made of alabaster. Chalky alabaste[...]
Luxurious furniture in lightweight marble
Dedalo is a company from Carrara that designs and produce monolithic luxurious furnishings in lightened marble, with a contemporary design. Our goal is to reaffirm the use of marble in everyday life without renouncing, for reasons of weight, to its three-dimensional vocation, proposing sculptural and extremely engaging shapes.
D.E.SIGN S.r.l.
Viale Galileo Galilei, 32
54033 Carrara (MS)
Italia
[email protected]
+39 338 88 73 907
P.I./C.F. 01268660451
Registro Imprese di Massa Carrara
REA Number 127201
Cap. Soc. 10000 € i.v.
Technical cookies are necessary for the functioning of the website because they enable functions to facilitate user navigation, who for example can access their profile without having to log in each time or can select the language in which they want to browse the site without having to set it whenever.
Cookie | Type | Duration | Description |
---|---|---|---|
_GRECAPTCHA | persistent | 1 year | Cookie installed by Google reCAPTCHA, a SPAM protection service provided by Google LLC or by Google Ireland Limited, depending on the location in which this site is used. |
_icl_current_language | persistent | 1 year | This cookie is used by the WordPress WPML plugin and is used to remember the language code of the last page visited. |
cli_user_preference | persistent | 1 year | The cookie is used to memorize the selection of the consent given to the use of cookies. It does not store any personal data. |
cookielawinfo-checkbox-cookie-analytics | persistent | 1 year | Track the acceptance of the type of cookie. |
cookielawinfo-checkbox-necessary | persistent | 1 year | Track the acceptance of the type of cookie. |
CookieLawInfoConsent | persistent | 1 year | The cookie is used to store the summary of the consent given for the use of the cookie. It does not store any personal data. |
SEARCH_SAMESITE | persistent | 1 year | Google cookie used to prevent the browser from sending cookies along with cross-site requests |
viewed_cookie_policy | persistent | 1 year | The cookie is set by the GDPR Cookie Consent plug-in and is used to store whether the user has consented to the use of cookies or not. It does not store any personal data. |
wordpress_test_cookie | persistent | 1 year | Technical cookie installed by Wordpress to check if the user's browser is set to accept or not accept cookies. |
wp-settings-1, wp-settings-time-1 | persistent | 1 year | This cookie is used by WordPress to customize the display of the administration interface and, possibly, also the interface of the main site. |
wp-wpml_current_language | persistent | 1 year | This cookie is used by the WordPress WPML plugin and is used to remember the current language code. |
Profiling cookies and social plugins, which can be first or third party, are used to track the user’s navigation, analyze his behavior for marketing purposes and create profiles regarding his tastes, habits, choices, etc. In this way, for example, it is possible to transmit targeted advertising messages in relation to the user’s interests and in line with the preferences expressed by them in online browsing.
Cookie | Type | Duration | Description |
---|---|---|---|
__Secure-3PAPISID, __Secure-3PSID, __Secure-APISID, __Secure-HSID, __Secure-SSID, __Secure-3PSICCD | persistent | 1 year | Used for the purpose of targeting to create a profile of the interests of website visitors to show relevant and personalized ads from Google and to protect the site from SPAM and malicious access. |
__Secure-3PSIDCC, __Secure-3PAPISID | persistent | 1 year | Cookie installed by Google services. Create a website visitor interest profile to show relevant and personalized ads through retargeting. |
NID, PREF, SID | persistent | 1 year | Google uses cookies, such as PREF, NID and SID cookies, to help personalize ads on Google properties, such as Google Search. For example, we use them to store your most recent searches, your previous interactions with an advertiser's ads or search results and your visits to an advertiser's website. This way we can show you personalized ads on Google. |
Analytical cookies, which can be first or third party, are installed to collect information on the use of the website. In particular, they are useful for statistically analyzing accesses or visits to the site itself and to allow the owner to improve its structure, navigation logics and contents.
Cookie | Type | Duration | Description |
---|---|---|---|
_ga | persistent | 1 year | Cookie installed by Google Analytics. It allows you to monitor and analyze traffic data to the site and store information anonymously. |
_gat | persistent | 1 year | Cookie is installed by Google Analytics. Used to limit the frequency of requests. |
_gat_gtag_ | persistent | 1 year | Cookie installed by Google Analytics. Collects information anonymously on how visitors use the site. |
_gid | persistent | 1 year | Cookie installed by Google Analytics. It allows you to monitor and analyze traffic data to the site and store information anonymously. |
SID, SAPISID, APISID, SSID, HSID, NID, PREF, 1P_JAR | persistent | 1 year | These cookies are used by Google Maps, YouTube and other Google applications to store user preferences when viewing maps, videos and to keep track of visitor behavior. |