Offer for subscription closes

Tertiary Minerals PLC 27 April 2005 April 27, 2005 www.tertiaryminerals.com DIAMOND SUBSIDIARY'S OFFER FOR SUBSCRIPTION CLOSES OVER-SUBSCRIBED • Subscriptions received for £450,335 • Tertiary Retains 20,000,000 shares in Sunrise Diamonds plc • Further Fundraising Begins In Preparation For AIM Admission Tertiary Minerals plc ('Tertiary') is pleased to announce that its subsidiary, Sunrise Diamonds Plc ('Sunrise'), has successfully completed an offer for subscription of up to 30,000,000 ordinary shares at 1p each ('the Offer'). The Offer, which was heavily oversubscribed, also included an offer to existing Tertiary shareholders whereby each Tertiary Shareholder (other than those resident overseas) was offered 1 Ordinary Share in Sunrise for each 2 ordinary shares held in Tertiary. Under the terms of the Offer the directors of Sunrise also reserved the right to issue an additional 10,000,000 Ordinary Shares if the Offer was over-subscribed. Valid subscriptions had been received for 45,033,514 Ordinary Shares in Sunrise when the offer closed at 3.00pm on 26 April 2005. As a result, the Offer, designed as a seed corn opportunity for Tertiary shareholders, will have raised between £300,000 and £400,000 before expenses depending on the extent to which the Directors of Sunrise utilise the over-subscription facility. Funds raised will be used for Sunrise's working capital and to meet the costs of the planned admission of Sunrise to trading on AIM. Tertiary will retain 20,000,000 shares in Sunrise. Shareholders will be informed of their allocations when share certificates in Sunrise are sent out, by 5 May 2005. As has previously been indicated, Sunrise plans to carry out further fundraising following the close of the Offer and prior to admission of Sunrise's shares to trading on AIM. Additional funds will be used for exploration of Sunrise's Finnish diamond interests. Sunrise has appointed Ruegg & Co as Nominated Adviser and W.H.Ireland will be its Broker. Sunrise has acquired rights to all of Tertiary's diamond interests in Finland including three kimberlites in the Kuusamo area of the Karelian Craton which were drilled last year and 45 other untested targets in the same area of this craton. The initial work programmes for these targets will include ground magnetic surveys, till sampling and diamond drilling. Further Information: Patrick Cheetham, Tertiary Minerals Plc. Tel: 01625-626203. Mobile: 07767-458751 John Greenhalgh/Ron Marshman, City of London PR Ltd. Tel: 020-7628-5518 Laurie Beevers, W.H.Ireland, Tel: 0161 832 2174 This information is provided by RNS The company news service from the London Stock Exchange