Finnish Diamond spin-off

Tertiary Minerals PLC
29 March 2005


                             TERTIARY MINERALS PLC


                 TERTIARY TO SPIN-OFF FINNISH DIAMOND INTERESTS

   • 1-for-2 Issue At 1p Designed As 'Seed' Opportunity Before AIM Float
   • Detailed Exploration Planned For Previously Unrecognised Kimberlite
     Cluster
   • Prospects Include Three Kimberlites And Forty-Five Untested Targets
_____________________________________________________________________

Tertiary Minerals plc ('Tertiary Minerals' or 'the Company') is pleased to
announce that it's wholly-owned subsidiary, Sunrise Diamonds plc ('Sunrise
Diamonds'), is expected to make a public offer of shares ('the Offer') to raise
funds to meet the costs of making an application for admission to trading on AIM
and for general working capital purposes.

Sunrise Diamonds has acquired the rights to the diamond interests in Finland
held by Tertiary Minerals' wholly owned subsidiary Tertiary Gold Limited
('Tertiary Gold'), details of which are summarised in the Company's last annual
report. These interests comprise rights to three kimberlites discovered by
Tertiary Gold last year in a previously unknown kimberlite cluster, now known as
the 'Kuusamo cluster', and an exciting portfolio of 45 untested kimberlite
targets in the same general area.
The Offer by Sunrise Diamonds proposes to raise up to £300,000 before expenses
and will comprise an offer of up to 30,000,000 new Ordinary Shares at 1p per
share. The Offer is being structured to include an Entitlement Offer of up to
23,210,547 new Ordinary Shares to eligible Tertiary Minerals shareholders on the
basis of :

    1 share in Sunrise Diamonds for every 2 shares held in Tertiary Minerals

Eligible shareholders will be able to apply for more (or less) shares than is
their entitlement. Sunrise Diamonds will reserve the right to issue a further
10,000,000 shares at 1p in the event of over-subscription.

Currently there are 20,000,000 ordinary shares in issue in Sunrise Diamonds, all
held by Tertiary Minerals and its wholly-owned subsidiary Tertiary Gold Ltd, and
30,000 redeemable Preference shares of £1 each held by Tertiary Minerals.

Following the Offer, after redemption of the preference Shares and assuming full
subscription but not over subscription, Tertiary Minerals will hold 40% of
Sunrise Diamonds.
The Offer is being structured to allow Tertiary Minerals shareholders a more
direct and entry-level participation in the Company's diamond exploration assets
and it is consistent with the Tertiary Minerals' Chairman's stated objective to
build on the value inherent in the Company to the benefit of its shareholders.

The Record Date for the Offer to Tertiary Minerals shareholders is expected to
be 29 March 2005 and Sunrise Diamonds expects to publish and post its prospectus
on Friday 1 April 2005. The Offer is expected to open on 4 April 2005 and close
on 26 April 2005.

Any decision to take shares in the Offer should be based on the prospectus to be
issued and not on this announcement which is issued for information purposes
only.

Sunrise Diamonds intends to carry out further fundraising following the close of
the Offer and make application for admission to AIM. The objective of the
further funding will be to fund the exploration of the Company's diamond
interests and for working capital purposes. The effect of such further
fundraising will be to dilute the shareholdings of the shareholders immediately
following the offer.

It will be a condition of acceptance of the Offer not to sell the Offer Shares
for 12 months from the date of closing of the Offer or 6 months from admission
to AIM (whichever is the sooner).

Expected timetable of key events :

Record Date for the Offer                                        Close of
                                                                 business on 29
                                                                 March 2005
Latest time and date for splitting of Applications Forms (to     3.00 p.m. on 22
satisfy bona fide market claims only, where Tertiary Minerals    April 2005
Shareholders have sold part of their shareholding prior to the
ex-entitlement date)
Latest time and date for receipt of completed Application Forms  3.00p.m. on 26
and payment in full under the Offer                              April 2005
Dispatch of definitive share certificates for the Offer Shares   5 May 2005

For further information please contact:

Patrick Cheetham, Executive Chairman, Tertiary Minerals plc. Tel: [phone]
Ron Marshman/John Greenhalgh, City of London PR Limited. Tel: [phone]



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