Vinga is a small island 10 nautical miles (19 km; 12 mi) outside Gothenburg's harbour entrance in Sweden. The 19th century Vinga Lighthouse is noted, not only as a beacon in the waterway of the Swedish west coast, but also as the place where the Swedish poet laureate Evert Taube grew up. Today Vinga is a tourist attraction, with boats to and from Gothenburg harbour.
The bedrock of Vinga is mostly made up of porphyrite (porfyrit), a volcanic rock with less Silicon dioxide, SiO2, than Porphyry. The rock has a fine-grained structure, dark with lighter grains of feldspar and other minerals. The mineralogical composition of the Vinga porphyry classifies it as a monzogranite or quartz diorite. The northern part of the island contains orthopyroxene. The Vinga porphyry was created about 950 million years ago, when it penetrated the surrounding older gneiss rock.
^Årebäck, H; Andersson, UB; Petersson, J (2008). "Petrological evidence for crustal melting, unmixing, and undercooling in an alkali-calcic, high-level intrusion: the late Sveconorwegian Vinga intrusion, SW Sweden". Contributions to Mineralogy and Petrology (93): 1–46.|accessdate= requires |url= (help)