A Brief Geology

The Highlands are now the mere peneplaned stumps
of what were once the highest peaks of the Caledonides,
a fold mountain belt stretching from Canada
and north-eastern USA in one direction
(the Appalachians and their associated subordinate chains) to Norway and Sweden in the other.

Unlike most of the British Isles, Scotland comprised
an ancient continent encompassing parts of
Canada, USA and Greenland.

This has a special interest for fossil collectors,
as faunas from Scotland generally differ from those of southern Britain during this period.

The North-West Highlands has a complex and interesting geology with some of the oldest rocks in the United Kingdom - over 3,000 million years old, in some cases.

ACTINOLITE - Loch Alsh, Ross & Cromarty.
(specimen: 65x55mms).

The city of Perth is termed the "gateway to the Scottish Highlands". The majority of the county lies north of the Highland Boundary Fault in the Highlands region,
and for convenience, is included here.

There are several localities in the county well-known for agate-collecting, such as the Glen Farg area, and others as gold panning sites. (see gold page). A 6 gram nugget was encountered in 2003 near Aberfeldy. The find caused concern as the publicity created, attracted members of the general public to try their luck. The area of the find is on an SSSI site and, therefore, collecting was not permitted.

Creamy to pale green coloured, crystallized tremolite,
as interesting specimens, has also been found in Perthshire in the Trinafour area, near Kinloch Rannoch.

Previously identified as edenite, these examples have revealed themselves to be tremolite, as a result of further analyses. (S. Moreton, pers. comm, 2005).

TREMOLITE - Trinafour, Kinloch Rannoch, Perthshire.
Pale green bladed aggregates; spec: 55x40mms.

Other rare barium species have been reported recently, though mainly as micro-specimens.

Specimens of the strontium mineral, celestite, have also been recovered from a site near Blair Atholl, as white-pale grey/bluish toned crystals.

The Ben Lawers/ Lochan na' Lairige area is well-known
for rutile specimens. Sulphide minerals also occur here
and elsewhere in the county.

Recent investigations at the Tomnadasan Mine, also known as the Tayside Mine, have rendered interesting examples
of tennantite-tetrahedrite crystals on pyrite,
with traces of secondary species.

CELESTITE - Blair Atholl, Perthshire.
Intergrown bladed crystals to over 2cms.

RUTILE - Lochan na' Lairige, Ben Lawers, Perthshire.
Red-brown, lustrous bladed crystals to 2cms.

TENNANTITE - TETRAHEDRITE
Tomnadasan Mine, Loch Tay, Perthshire. (crystals to 1cm).

MUSCOVITE - Garve, Ross & Cromarty.
Platy aggregates to 80mms.

MOLYBDENITE
Coire Bhuidhe, Glen Creran, Argyll.
25x13 mms crystal on quartz.

ARGYLL

In Argyll, small pyrite cubes are found at Ballahuilish
from slate quarries in that area; and at Tyndrum,
there is an occurence of "fuchsite", a green, Chromium-rich
variety of muscovite. Tyndrum itself is a gold-panning site.

Keen Scottish collectors re-discovered a fine molybdenite locality some years ago - with silvery, platy crystals
to over 2 cms and occasionally larger masses
in a skarn-type deposit.
Epidote can also be found here in small crystal groups.

At Loch Lochy, graphite is found in veins and, on the peninsula of the Mull of Kintyre, at Kilmartin, blue, bi-pyramidal anatase crystals may be encountered.

A recent noteworthy and new find of garnet was uncovered near Ben Resipol, close to Strontian, (2004). This pegmatite material has yielded crystals to 2cms in matrix. The finest however are the smaller blood-red, gemmy crystals.

At Lochgilphead, both primary and secondary species
have been found in an old copper deposit.

Strontian, with its world famous occurences of harmotome, brewsterite and strontianite, is also in the county of Argyll,
but is dealt with separately. (see link below)

PIEMONTITE - Glencoe, Argyll, SCOTLAND.
Raspberry-red crystals to c. 2mms. in a radiating spray.

This locality yields radial, acicular crystals of epidote (withamite variety), either embedded in the matrix
or in small cavities.