De Beers Reports Modeled Revenues Per Carat for Mountain Province Diamonds' Hearne and 5034 Diamond Pipes; C$10 Million Winter Bulk Sample Program Planned.

Business Editors

ONTARIO, Calif.--(BUSINESS WIRE)--Dec. 18, 2001

Mountain Province Diamonds Inc. (OTCBB:MPVI)(TSE:MPV) announced that it has received from its joint-venture partner De Beers Canada Exploration Inc. (De Beers Canada), a wholly owned subsidiary of De Beers Consolidated Mines Ltd. (De Beers), modeled revenue per carat estimates for the 5034 and Hearne diamond pipes.

The modeled values are down slightly from those reported for the 1999 bulk sample, but are consistent with or less than the drop in values in the rough diamond market. The 9.9 carat diamond recovered from the 5034 pipe is of high quality and top color and was valued at approximately U.S. $60,000.

De Beers is planning to bulk sample the 5034 and Hearne pipes this winter in order to recover more high-quality diamonds. The 5034 and Hearne kimberlite pipes are two of the largest and have the two highest values of the five diamondiferous bodies in the cluster at Kennady lake, located within the joint-venture's AK claims in the Northwest Territories of Canada.

As was mentioned in the Sept. 20, 2001 news release, De Beers completed the winter 2001 bulk sample program of the Hearne and 5034 kimberlite pipes in early May. The 1,665 carats that were recovered from both pipes (to a 1.5mm lower cut-off) plus the diamonds recovered from the 1999 bulk sample were all valued, based on August 2001 diamond prices, at The Diamond Trading Co. (DTC) in London.

The De Beers Mineral Resources Estimation Department in Johannesburg has used these values for both bulk samples to update the modeled revenue per carat for each pipe. It is important to note that production recovery factors, determined by De Beers, have been applied and that the commonly used commercial bottom cut-off recovery size screen with a 1.50 mm square mesh has been used.

De Beers has recently changed the way diamond values are reported to the company to make them comparable to the values reported by other Canadian diamond mining companies. To compare the 1999 and the current values, 10% has to be added to the 1999 values.

The average revenue per carat for the 5034 pipe based on August 2001 values is U.S. $65.50 for the combined 1999 and 2001 parcels, compared with the adjusted U.S. $69.30 value for the 1999 bulk sample. Similarly the average revenue per carat for the Hearne pipe is U.S. $63.30 compared with the adjusted U.S. $71.50 value for the 1999 bulk sample.

According to analysts and industry sources, the prices of rough diamonds have fallen by an average of around 20% during the recession of the past year and at least 10% since late 1999. The decreases in value for the diamonds from the 5034 and Hearne pipes are thus consistent with or less than the large drop in the rough diamond market values.

The 9.9 carat diamond recovered from the 5034 pipe this past winter is of high quality and top color and was valued by the DTC at approximately U.S. $60,000. The company's consultant, Overseas Diamonds N.V. from Antwerp, Belgium valued representative parcels of the diamonds at the DTC in November.

Their values for selected parcels were within several percent of the De Beers' values for those same parcels.

It was observed at the DTC that a population of high-quality diamonds (such as that of the 9.9 carat diamond) exists amongst the diamonds recovered to date from the Hearne and 5034 pipes. This observation and additional follow-up analysis of these diamonds has led De Beers to the decision that more bulk sampling of the Hearne and 5034 pipes is now needed.

More high-quality diamonds need to be recovered so that their size frequency distribution can be determined more accurately. These high-quality diamonds have a large impact, especially the larger ones, on the revenue per tonne so the more accurately their size frequency distribution is known, the greater the confidence in and the accuracy of the revenue modeling.

These high-quality diamonds offer upside potential to the values per carat. The occurrence of the very valuable 9.9 carat stone poses the possibility that these stones could occur regularly during production.

The winter bulk sample program is planned to consist of 8 to 10 large diameter drill holes (4-5 into each pipe) to recover at least 2,000 carats. The same drill (24-inch diameter) as used last year will be used and is on site as is some of the supporting equipment. Additional equipment will be flown in as soon as the ice is thick enough to support a Hercules aircraft.

A team is already in the camp and thickening of the ice has already started. De Beers estimates that the bulk sample will cost approximately C$10 million.

Dr. Jan W. Vandersande, president and CEO, stated: "The company is very pleased with the results considering the weak diamond market of the past year. The presence of high-quality diamonds and De Beers' decision to recover more of them, clearly offers upside potential to the values per carat."

Mountain Province Diamonds is a diamond exploration and development company. The AK and CJ claims, located in the Northwest Territories of Canada are now held 44.1% by Mountain Province Diamonds, 4.9% by Camphor Ventures (CDNX:CFV), and 51% by De Beers Canada Exploration.

As reported in its news release on March 7, 1997, Mountain Province Diamonds and its partner entered into a joint agreement with De Beers Canada Exploration, formerly known as Monopros Ltd. (a wholly owned subsidiary of De Beers Consolidated Mines Ltd.), under which De Beers Canada Exploration has the right to earn up to a 60% interest in the AK and CJ properties by taking the project to commercial production.

This release may contain forward-looking statements, within the meaning of the "safe-harbor" provision of the Private Securities Litigation Reform Act of 1995, regarding the company's business or financial condition. Actual results could differ materially from those described in this news release as a result of numerous factors, some of which are outside of the control of the company.