Silicate-rich marble
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

Silicate-rich marble

This silicate-rich marble of the Lewisian group was originally deposited as a limestone in the Late Archean. It has been subjected to granulite-grade metamorphism at temperatures reaching 800 °C and depths of around 30 km during the Laxfordian orogeny. Although the island of Tiree is dominated by biotite-hornblende gneiss, there are several bands of garnet-biotite schists, siliceous schists, calc-silicate rocks and marbles representing metasedimentary rocks. This marble is one of several prominent pink-coloured bands that have been used as a decorative stone.

In thin section, the sample can be seen to contain abundant rounded and sometimes deformed dark crystals of pyroxene (diopside) and hornblende within a fine-grained crystalline carbonate groundmass. The thin section sample was contributed by David Anderson (a collector based in Girvan) and the hand specimen comes from the Hunterian Museum (Glasgow University).

Additional images
56.523549, -6.855656
Balephetrish quarry, Isle of Tiree, NW Scotland
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
Accessory minerals
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: