agates of scotland

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"Scotch Pebbles" - Scottish Agates

This variety of quartz can make beautiful objects when fragments and sliced nodules are polished up to allow their natural beauty to shine..

Though Scotland may not produce the largest agates found in the world, Scottish agates nevertheless rank among the best as a result of their variety in form and for the subtleness of their colouring.

"Scotch pebbles" are agates or agate fragments commonly collected from beaches after being worn out of the host rock. Agates are to be also found in situ (in the host rock).

Some locations of either type have been over-collected in the past and are no longer very productive; while others can give surprises...

Agates from Scotland are found in situ in the andesite and basalt lavas of Devonian age located in the Midland Valley.

There are two main areas in Scotland where these lavas are to be found - in the east, centred around the former counties of Angus, Fife and Perthshire and, on the SW coast, in Ayrshire.

Moss AGATE - Heads of Ayr, Ayrshire, Scotland.
A single agate showing three distinctive habits:fortification, scenic and with moss inclusions. (size: c. 75x50mms).

Agates may also be found in the Tertiary basalt lavas of some areas on the west coast such as the islands of Mull and Skye.

In all of these areas, beach agates can be found. Where the lavas extend out to sea, agates can be weathered out by sea erosion and subsequently washed onto nearby beaches by the action of currents.

The agates of the Devonian lavas generally have a wide variety of colouring and form. These lavas, which are over 400 million years old, are often the source of the best agate specimens to be found in Scotland.

The Tertiary basalt lavas, on the other hand, weighing in at around 55-60 million years in age, have a more restrictive colour palette to impart upon the agates they produce, in comparison to their Devonian relations.

SCOTTISH AGATE LOCATIONS

Map showing (in dark text) some of the more important agate-bearing areas of Scotland.

Agate Types

This is basically a means of describing the form or pattens that are found on polished slices of agates. Nearly all the generally accepted, descriptive agate forms are to be found in Scotland. Such examples include hemi-agate, sagenitic agate, onyx agate, moss agate, scenic agate... to name but a few common terms.

However, it is the more common "fortification agate", of typically concentric banded patterns, which is prevalent throughout most agate-bearing areas of Scotland. Vein agate is far more restricted in its occurence.

It is quite possible to find two or more agate forms on the one example. Similarly, some sites can render a wide array of agate forms, while others are more limited with their patterns.

Locations

Some locations throughout Scotland are justly renowned for the quality of agates they have produced. However, some of these sites are now, unfortunately, almost history.

The factors which have caused this vary from the precise location having been lost through time, the sites are now difficult or impossible to access or, simply, the occurence has become exhausted.

Examples of these include the classic "Blue Hole" site near Montrose, in Angus, or that of Burn Anne in Ayrshire.

New collecting sites are occasionally uncovered. Prime examples include Ethiebeaton and Ardownie Quarry, Monifieth, both near the city of Dundee, in the old county of Angus, Tayside Region.

Specimens from the latter site were rated of the best quality for Scotland. Unfortunately, the locality was short-lived and is no longer accessible.

EASTERN SCOTLAND:
Agates are found in Angus, particularly the Montrose area, the northern side of the Tay Estuary around Dundee and inland, in the Sidlaw Hills. Farther north, they are also to be found in Kincardineshire.

Other sites include the southern side of the Tay Estuary and the Ochil Hills, both in Fife - with the Norman Law area being particularly well-known and productive.

Further inland, in Perthshire, there are also numerous sites. Some of these are famed for their distinctive agates though some regrettably now are also apparently exhausted.

SOUTH-WEST SCOTLAND:
Devonian agates are found in the county of Ayrshire around Dunure, south of the town of Ayr, and farther south. Small restricted occurences, where these rocks outcrop at the surface, are also found inland.

SOUTHERN UPLANDS:
Another agate area of note is the Cheviot Hills in the Southern Uplands - straddling the border region of England and Scotland. Several agate types, including vein agate are found.

TERTIARY LAVAS:
The Tertiary basalt lavas of the west coast of Scotland are better known for their zeolite mineral specimens. Agate localities are less common and/or less well known.

Nevertheless, agates are to be found on the islands of Mull and Rhum and elsewhere. New finds remain to be made.

Agates and Inclusions

Other minerals may be found as inclusions in agates. Commonly, these minerals are calcite, dark green, "mossy" celadonite and occasionally fibrous/ acicular, zeolite mineral species ("sagenitic agates").

Quartz varieties such as rock crystal, smoky quartz and amethyst are also found in agates. Some agates from the Tertiary lavas of Mull contain inclusions of very small, simple cubic crystals of golden pyrite. Calcite is another mineral that is found in agates nodules.

NOTE
Permission is normally required to gain access to most inland localities and this should be sought from the relevant authorities beforehand!

References/ Further Reading

Books

"Agates" H.G. MacPherson. (National Museum of Scotland & British Museum (Natural History) (1989). publication.).
"Scottish Agates" - N. Crawford & D. Anderson (Lapidary Stone Publications) (2010),

UK Journal of Mines & Minerals

vol. 7 pp. 13-17 "Colour in Scottish Agates." R. Field. (1989).
vol. 14 pp.17-20 "Agates from Ardownie Quarry, Monifieth, Tayside, Scotland." S.M. Ingram. (1994).

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More agate photographs can be found on the Central Scotland East & Ayrshire & Lanarkshire pages (links at top)

Fortification/ "Eye" AGATE
Norman's Law, Ochil Hills, Fife, Scotland.