NOTIFICATION OF MAJOR INTEREST IN SHARES

For filings with the FSA include the annex

For filings with issuer exclude the annex

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached: ii

PETRA DIAMONDS LTD

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

X

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights

Other (please specify):

3. Full name of person(s) subject to thenotification obligation: iii

T. Rowe Price Associates, Inc.

4. Full name of shareholder(s)  (if different from 3.):iv

Chase Nominees Ltd.

State Street Bank & Trust Co

Northern Trust Co.

Bank of New York Mellon Bank, N.A.

5. Date of the transaction and date onwhich the threshold is crossed orreached: v

24 July 2012

6. Date on which issuer notified:

25 July 2012

7. Threshold(s) that is/are crossed orreached: vi, vii

5%

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights x

Direct

Direct xi

Indirect xii

Direct

Indirect

BMG702781094

25,808,996

25,259,347

25,904,996

25,355,174

5.01%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date xvii

Exercise/Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

25,335,174

5.01%

9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable: xxi

T. Rowe Price Associates, Inc. (TRPA) serves as investment adviser, with dispositive and voting authority, to various institutional clients that own shares of Petra Diamonds Ltd., including the T. Rowe Price New Era Fund, which owns 10,646,222 shares. Such shares are registered in the following name(s):

Chase Nominees Ltd. - 5,616,770

State Street Bank & Trust Co. - 17,105,960

Northern Trust Co. - 809,574

Bank of New York Mellon Bank, N.A. - 1,822,870

Proxy Voting:

10. Name of the proxy holder:

11. Number of voting rights proxy holder will ceaseto hold:

12. Date on which proxy holder will cease to holdvoting rights:

13. Additional information:

14. Contact name:

Dorothy Jones, Assistant Vice President, T. Rowe Price Associates, Inc.

15. Contact telephone number:

001 410 345 6603

Note: Annex should only be submitted to the FSA not the issuer

Annex: Notification of major interests in share

A: Identity of the persons or legal entity subject to the notification obligation

Full name

(including legal form of legal entities)

T. Rowe Price Associates, Inc.

Contact address

(registered office for legal entities)

100 East Pratt Street, Baltimore, MD 21202

Phone number & email

001 410 345 6603

[email protected]

Other useful information

(at least legal representative for legal persons)

B: Identity of the notifier, if applicable

Full name

Contact address

Phone number & email

Other useful information

(e.g. functional relationship with the person or legal entity subject to the notification obligation)

C: Additional information

For notes on how to complete form TR-1 please see the FSA website.