Provenite

Los Catalanes Gemological District

AreaActiveDraft data

30.7928° S, 56.2703° W · ± 10 km

Amethyst from Artigas, Uruguay, with photos of specimens from this locality.

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Minerals found here

Amethyst

Amethyst at Los Catalanes Gemological District

Giant, intensely purple amethyst-filled geodes hosted in basalt flows

Amethyst stalactite about 18 cm long with crystals around the outside and a polished base showing growth rings, from Artigas, Uruguay.
Amethyst stalactite about 18 cm long with crystals around the outside and a polished base showing growth rings, from Artigas, Uruguay.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Large amethyst stalactite about 19 cm long with a polished base showing successive growth layers, from Artigas, Uruguay.
Large amethyst stalactite about 19 cm long with a polished base showing successive growth layers, from Artigas, Uruguay.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Rounded knob of amethyst crystals about 16 cm across, covered all around with deep purple crystals, from Artigas, Uruguay.
Rounded knob of amethyst crystals about 16 cm across, covered all around with deep purple crystals, from Artigas, Uruguay.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Formula
SiO₂
Morphology
Crystal-lined giant geodes; cylindrical in pahoehoe flows, oblate or irregular in aa flows
Typical size
Geodes from about 50-70 cm (flow 2) to about 2 m (flow 4); giant geodes up to about 5 m and roughly 10-20 tonnes (flow 3, aa-type)
Color / luster
Intense purple, shiny crystals; brownish hematite inclusions often present
Associated minerals
Colourless quartzchalcedonybanded agatecalciteceladoniteprasiolite (occasional)
History
Deposits known since about 1750; first detailed survey by the Geological Survey of Uruguay in 2007; reputed to hold the largest amethyst-filled geodes found

Sources: SRC-104 SRC-105

About Amethyst →

Geology of the locality

Setting
Amethyst and agate geodes in Early Cretaceous Parana-Etendeka flood basalt (Arapey Formation) flows, mineralised by low-temperature groundwater
Host rock
Basalt
Region
Artigas
Country
Uruguay

Coordinates (30 47 34 S, 56 16 13 W) taken from the IUGS geoheritage entry for the district; the district is about 60 km south of Artigas town. Several companies mine here.

Sources: SRC-104 SRC-105

Sources

  1. SRC-104 · Article
    Amethyst and agate geodes of the Los Catalanes district, Uruguay (title not captured; Springer article s00126-024-01310-2)2024 · Mineralium Deposita
  2. SRC-105 · Website
    Deposits of amethysts of Los Catalanes gemological districtIUGS Geoheritage

Draft data from the Provenite workbook. Check entries against the cited sources before relying on them. Photos are open-licence images from Wikimedia Commons; the author and licence are given with each photo.