Wollastonite skarn - Omey Island
Click the microscope button to view a thin section for this sample.
Click the microscope button to view a thin section for this sample.

Fact sheet

Wollastonite skarn - Omey Island

This carbonate rich contact metamorphic rock or skarn comes from Omey Island a tidal island 500m from the coast of Galway, Ireland. The Island is mostly formed of porphyritic granite and while few live on the island today, it has been inhabited for long periods of time. A ruined medieval Parrish church, Teampaill Feichin, was excavated from the deep sand covering parts of the island in 1981, and stands on the site of an earlier abbey said to have been founded by Saint Feichín.

The thin section exibits coarse grained calcite with lamellar strain twins, large poikilitic garnet with multiple inclusions. The pyroxenoid wollastonite is also abundant in this thin section, and appears in fibres and blades, particularly in the lower left hand quarter. Vesuvianite is also reported in this thin section.

Additional images
  • Wollastonite skarn - Omey Island
  • Wollastonite skarn - Omey Island
53.535278, -10.1575
Omey Island County Connemara, Ireland
About this collection

The United Kingdom Virtual Microscope (UKVM) collection consists of igneous, sedimentary and metamorphic rocks from around the UK.

It is intended as a teaching resource, helping to tell the story of the common rock types and how they form, and reflecting the history of the UK at the margins of the continent of Europe. The collection is a series of teaching sets, for example igneous rocks from the North Atlantic Igneous Province and SW England; high-temperature metamorphic rocks from Scotland and low-temperature metamorphic rocks from Wales; and sedimentary rocks, including English limestones and sandstones.

Sample details

Rock-forming mineral
grossular garnet
Category guide  
Category Guide
Refers to any word or phrase that appears in the individual rock names. Names are generally descriptive; they allow users to search for broad terms like ‘granite’ as well as more specific names such as ‘breccia’. However, the adjacent descriptions of the specimens captures a wider range of general words and phrases and is a more powerful search tool.
Refers to any word or phrase that appears anywhere in the descriptions of the specimens
Accessory minerals
Minerals that occur in very low abundance in a rock. They are usually not visible with the naked eye and contribute perhapssver, they often dominate the rare elements such as platinum group metals.
Rock-forming minerals
Minerals that make up the bulk of all rock samples and are also the ones used in rock classi?cation.
Selecting one or more period, for example 'Jurassic'.
A term used to group together related samples that are not already gathered into a single Collection. For instance, there is a ‘SW England granites’ theme that includes such rock types as granite, hydrothermal breccia, skarn and vein samples.
A general term used to label a rock sample. It is a useful way of grouping similar samples throughout a collection. Category names are often, but not exclusively, common rock names (e.g. granite, basalt, dolerite, gabbro, greisen, skarn, gneiss, amphibolite, limestone, sandstone).
The owner of the sample that appears in the collection. For example, NASA owns all the samples that appear in the Moon Rocks collection
We would like to thank the following for the use of this sample: