Minerals of Scotland

Scottish Highlands
The Grampians, Cairngorms & Moray Firth

Minerals of the Scottish Highlands

General Introduction & Geology
Minerals of The Cairngorms
Grampians - Moray Firth

including photographs of

beryl - manganite - grossularite - barite
quartz (smoky quartz - cairngorm stone/ morion)

CAIRNGORMS

This part of the Highlands can be rather inaccessible (more of a no-go area in winter - a time when it shows much of its beauty). It contains several important peaks, including Scotland's second highest, Ben Macdhui (2nd to Ben Nevis).

As a centre of glaciation during the last ice age, the effects of glaciation are quite apparent in the glacial troughs (glens) separating the interspersed plateaux.

Tors on some summits can attain heights of around 25 metres. The rocks themselves are the remnants of a granitic intrusion which appears to have been a laccolith.

The Cairngorm Mountains now form Britain's largest National Park area.

CAIRNGORM MOUNTAINS (height in feet).
Type locality" for dark smoky quartz, once known as "Cairngorm stone."

A Geological Profile

Next to Aberdeen, is what was once the largest hole in Europe - Rubislaw Quarry. Now history, the granite from Rubislaw graces many buildings in the city of Aberdeen, which proudly boasts the title of "The Granite City". Aberdeen is currently the main centre for offshore gas and oil exploitation in the North Sea.

The swarm of granitic intrusions straddling the Highlands - from the Strontian granite on the west coast, passing the Moor of Rannoch granite, to the intrusions of the east coast, including those of Aberdeen and Peterhead - belong mostly to the so-called "newer granites".

These granitic intrusions are mainly Silurian-Devonian in age and have their equivalents, in a lesser degree, in the central belt of Scotland and the Southern Uplands.

The intrusions vary in structure, rock texture and colour (from Aberdeen grey to Peterhead pink). Granodiorite is, however, fairly common to them all. Their volcanic associates, the Devonian lavas, are found further south, as in Angus, and are famed as the host rocks for the best agates found in Scotland.

The effects of glaciation are self-evident. However, metamorphism and mineralization is less noticeable and far more varied.

The region also boasts the earliest plant fossil ever found, at Rhynie, in Aberdeenshire, in sedimentary rocks of Devonian age.

CAIRNGORMS - Loch Avon.
(photo courtesy of R. Starkey, March 2004).

CAIRNGORMS - Cairn Lochan.
(photo courtesy of R. Starkey, March 2004)

MINERALS

BERYL
Cairngorm Mountains, Aberdeenshire.
1cm part-gemmy crystals.

SMOKY QUARTZ

(Cairngorm stone - Morion).

Small black crystals from the type locality area.

GROSSULARITE
Kingussie, Inverness.
Intergrown crystals to 15mms.

There are minerals throughout the Scottish Highlands yet to be found by collectors. But perhaps also, Mother Nature has eroded some of the finest away - many a while ago!

Garnets, epidote, clinozoisite, zoisite and other species such as actinolite, chrome diopside, talc... have a string of recorded occurences in the region.

The minerals of the Cairngorms are generally associated with granitic pegmatites. Beryl crystals (see photos above & right), topaz, microcline and quartz fragments, the traditional minerals of the mountains, are still occasionally found. More recently, micro examples of bertrandite and genthelvite have also been recorded.

Beryl also can be found, apart from the Cairngorm Mountains, in such scattered areas of the Scottish Highlands as Knoydart in the west or Ben Hope in the far north.

Lepidolite and micro elbaite (if you're very lucky!) are found near Ballater in a pegmatite environment.

In tin-tungsten veins in the same area, cassiterite and hubnerite as well as scheelite crystals, occasionally associated with small fluorite crystals and quartz, are some of the other minerals to be encountered in the Cairngorms.

BERYL - Bheinn a'Bhuird, Cairngorm Mountains.
A small, bi-terminated, naturally-healed crystal on smoky quartz.

North-East Scotland & Moray Firth

On the southern shores of the Moray Firth, there are several occurences of metamorphic minerals, including epidote, kyanite, garnet and cordierite. Barite crystals have also been found near Portknockie as crusts of small crystals.

At Portsoy (Banffshire), commercial extraction of such minerals once took place, particularly of talc.

At Lossiemouth (Moray), thin crusts of bright green pyromorphite have been found as well as much rarer,
well-formed small, grey-colourless phosgenite crystals
to a few millimetres. Other reported minerals include sphalerite, galena and marcasite.

The area is not really known for ore mineral species and their secondary derivatives, though there are numerous,
small occurences of manganese, lead and copper mineralization.

Outwith the Cairngorms proper, but still in the former county of Aberdeen, a variety of minerals can be found.

At Bridge of Don, just north of the city of Aberdeen itself, well-formed manganite crystals to a few millimetres have been found. Epidote also is found nearby as small crystal aggregates.

From the Frazerburgh area, groups of brownish vesuvianite crystals have been retrieved in recent years.

And, near Huntly, veins of xonotlite occur, associated with tacahranite and other species.

MANGANITE
Bridge of Don, Aberdeen, Aberdeenshire.
A group of crystals to c 2mms.

BARITE - Portknockie, Banffshire.
A 6mm crystal with zoned hematite inclusions.