International Minerals Corporation
FRANKFURT : MIW
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Swiss : IMZ

International Minerals Corporation

May 30, 2006 14:32 ET

International Minerals Increases Gold Resources at Rio Blanco with New Resource Estimate for High-Grade San Luis Deposit

SCOTTSDALE, ARIZONA--(CCNMatthews - May 30, 2006) -

Drill-hole Intercepts Include 1.2m at 126 g/t gold and 592 g/t silver

International Minerals Corporation ("IMC") (TSX:IMZ)(SWX:IMZ)(FWB:MIW) reports an updated mineral resource estimate (see Table 1 below) for the high-grade San Luis deposit at its Rio Blanco epithermal gold-silver project in southern Ecuador. The San Luis deposit is located immediately adjacent to the north of the Alejandra North deposit (see attached map), on which a positive feasibility study was announced by IMC on January 30, 2006.

Combining the new high-grade (approximately 25 g/t gold) Indicated Resource estimate at San Luis with the existing Measured and Indicated ("M&I") Resource estimate at the Alejandra North deposit, the total M&I Resource at Rio Blanco estimated to date by IMC is now approximately 661,000 ounces gold and 4.8 million ounces silver contained within 2.15 million tonnes at average grades of 9.5 g/t gold and 69 g/t silver (see Table 2 for details). The additional ounces discovered at San Luis represent an increase in total M&I Resource contained ounces of approximately 15% for gold and 8% for silver.

Drilling is ongoing at other high-priority target areas on the Rio Blanco property and IMC management is confident of finding additional high-grade gold-silver ounces on the property in the near future.

San Luis Deposit

In a news release dated December 12, 2005, IMC announced an initial Inferred Resource estimate for the San Luis veins based on 20 core drill holes totaling approximately 2,700m. The current Indicated Resource estimate is based on a total of 66 drill holes totaling 6,967m and is shown in Table 1 below. The area of drilling is shown on the attached map and previously-unreported drill results are shown in Appendix A.



Table 1. San Luis Deposit - Updated Mineral Resource Estimate
(Cut-off Grade 4.0 g/t gold)

--------------------------------------------------------------------
Gold Silver Contained Contained
Grade Grade Gold Silver
Category Tonnes (g/t) (g/t) Ounces Ounces
--------------------------------------------------------------------
Indicated Resource 108,000 24.9 107 86,000 371,000
--------------------------------------------------------------------
Inferred Resource 4,450 17.2 49 2,500 7,000
--------------------------------------------------------------------

Note: 1. Numbers are rounded to reflect the precision of a resource
estimate.
2. The contained gold and silver ounces are not mineral
reserves and do not have demonstrated economic viability.
3. "g/t" equals grams/metric tonne.
4. Grade cutting: gold grades above a 90 g/t "top-cut" grade
were reduced to 90 g/t. Silver grades above 400 g/t were
reduced to 400 g/t.
5. A specific gravity of 2.65 Kg/m3 was used to estimate the
tonnage.
6. The grades were interpolated using the "inverse distance
cubed" estimation technique.
7. The category of Measured Resource was not included due to
the difficulty in predicting the location and grade of the
very high-grade zones under the strict guidelines required
by National Instrument (NI) 43-101.
8. The contained metal estimates remain subject to mining
dilution and process recovery losses


This mineral resource estimate, effective May 30, 2006, was prepared internally in accordance with NI 43-101 by IMC's in-house Qualified Person, Technical Manager Nick Appleyard.

Combining the updated resource estimate at San Luis with the resource previously estimated in the January 2006 feasibility study for the Alejandra North deposit, results in the following total resource estimate generated to date for the combined Alejandra North and San Luis deposits:



Table 2. Alejandra North and San Luis Deposits - Combined Mineral
Resource Estimate

--------------------------------------------------------------------
Gold Silver Contained Contained
Grade Grade Gold Silver
Category Tonnes (g/t) (g/t) Ounces Ounces
--------------------------------------------------------------------
Measured Resource 144,000 11.6 99 54,000 456,000
--------------------------------------------------------------------
Indicated Resource 2,006,000 9.4 67 607,000 4,329,000
--------------------------------------------------------------------
Total M & I Resource 2,150,000 9.5 69 661,000 4,785,000
--------------------------------------------------------------------

--------------------------------------------------------------------
Inferred Resource 120,650 7.6 45 29,400 176,000
--------------------------------------------------------------------

Note: 1. Numbers are rounded to reflect the precision of a resource
estimate.
2. The contained gold and silver ounces are not mineral
reserves and do not have demonstrated economic viability.
3. "g/t" equals grams/metric tonne.
4. The Alejandra North resource estimate used a cut-off grade
of 3 g/t gold whereas the new San Luis resource estimate
used a cut-off grade of 4 g/t gold. Different cut-off
grades were used due to expected higher mining costs and
dilution impact for the relatively narrow veins in the San
Luis deposit compared to the Alejandra North deposit.
5. The contained metal estimates remain subject to mining
dilution and process recovery losses
6. For full details of the Alejandra North resource estimate,
see Press Release Dated January 26, 2005.


IMC is currently generating an updated mineral reserve estimation and mine schedule for the combined Alejandra North/San Luis deposits utilizing the new M&I Resource estimate shown in Table 2 above. This work is being carried out by Wardrop Engineering of Sudbury, Ontario and is expected to be finished at the end of June, after which IMC will update the economic parameters for the planned Rio Blanco underground mining operation. The addition of the high-grade San Luis gold-silver ounces is expected by IMC management to significantly enhance the overall economics of the Rio Blanco project as those ounces would be mined in the initial years of the mining operation.

Close-spaced drilling at San Luis was carried out on sections spaced 25m apart with an average spacing of 20m between drill holes on each section. Due to the high-grade nature of the veins and the possibility of over-weighting individual high-grade samples, the resource was estimated using an "inverse distance cubed" method on grade shells interpreted on vertical cross sections using down-hole 0.5m composited grades. Assay grades were reduced ("top-cut") to 90 g/t for gold grades above 90 g/t and to 400 g/t for silver grades above 400 g/t, based on a statistical breakdown indicated by cumulative frequency and probability plots of assay grade data. The effect of the grade cutting reduces total contained ounces of both gold and silver by approximately 10%.

Limited metallurgical test-work has been carried out by IMC on representative samples from San Luis and shows that the material is amenable to whole ore cyanidation using the proposed Rio Blanco process facilities. Test results to date show an average recovery of 87% for gold and 52% for silver. Due to the high-grade nature of the San Luis veins, additional test work is underway to evaluate the addition of a gravity circuit to the process plant.

Drilling to date in the San Luis area was carried out by Paragon Drilling Ecuador S.A., of Cuenca, Ecuador. Sample preparation was carried out by ALS Chemex in Quito, Ecuador using standard industry practices. Analytical work was carried out at the ALS Chemex laboratory in Vancouver, Canada, using conventional fire assay methods for gold and silver. For quality control purposes, analytical standards with known metal values were included with IMC's samples sent to ALS Chemex and show good reproducibility. Duplicate analyses of selected drill hole intervals sent to a second independent assay facility (CCI of Kellogg, Idaho) are incomplete, but initial results show good reproducibility. The overall drilling program was supervised by IMC's Qualified Person, Technical Manager, Nick Appleyard.

ON BEHALF OF THE BOARD

Stephen J. Kay, President and CEO

To view the map attached to this release please click on the following link: http://www.ccnmatthews.com/docs/0531imz.pdf



Appendix A. San Luis Deposit Drill Hole Results
Nominal 4 gm Au cutoff over minimum 1 meter interval

--------------------------------------------------------------------
Est.
True
Drill Hole Interval Length Width Gold Silver
(Depth-m) From (m) To (m) (m) (m) (g/t) (g/t)
--------------------------------------------------------------------
BC-206 to 216 These holes were previously reported on November 2,
2005
--------------------------------------------------------------------
BC-217 76.0 82.8 6.8 6.4 10.4 45
Includes: 76.0 77.4 1.4 1.4 36.2 154
96.3 98.0 1.7 1.3 5.4 54
--------------------------------------------------------------------
BC-218 2.7 4.2 1.6 1.5 6.4 109
--------------------------------------------------------------------
BC-219 No Significant Values
--------------------------------------------------------------------
BC-220 No Significant Values
--------------------------------------------------------------------
BC-221 8.8 10.8 2.0 1.4 7.5 44
Includes: 10.2 10.8 0.6 0.4 22.0 115
--------------------------------------------------------------------
BC-222 45.3 46.0 0.7 0.6 8.3 52
--------------------------------------------------------------------
BC-223 to 241 These holes are not located in the San Luis Zone
--------------------------------------------------------------------
BC-242 (87.8m) 6.2 8.3 2.1 1.7 5.6 53
--------------------------------------------------------------------
BC-243 (115.4m) 29.6 30.6 1.0 0.6 13.6 86
97.4 97.7 0.4 0.3 18.9 18
--------------------------------------------------------------------
BC-244 (130.2m) 49.3 49.5 0.2 0.2 81.8 509
--------------------------------------------------------------------
BC-245 (86.2m) No Significant Values
--------------------------------------------------------------------
BC-246 (122.8m) 36.6 37.8 1.2 0.9 21.2 158
--------------------------------------------------------------------
BC-247 (97.6m) 21.7 23.4 1.8 1.7 37.9 175
--------------------------------------------------------------------
BC-248 (48.4m) 38.4 39.6 1.2 1.1 10.3 73
--------------------------------------------------------------------
BC-249 (96.2m) 16.4 16.9 0.5 0.5 85.7 261
19.5 20.2 0.7 0.7 23.6 71
--------------------------------------------------------------------
BC-250 (109.4m) 31.2 32.1 0.9 0.8 36.2 231
--------------------------------------------------------------------
BC-251 (48.4m) 28.7 29.3 0.6 0.6 6.7 14
--------------------------------------------------------------------
BC-252 (120.1m) 15.3 16.4 1.1 0.9 71.6 381
--------------------------------------------------------------------
BC-253 (141.8m) 38.1 39.7 1.6 1.5 11.3 83
121.0 121.6 0.6 0.5 92.0 103
--------------------------------------------------------------------
BC-254 (120.0m) 21.1 25.0 3.8 3.5 17.6 113
Includes: 22.0 22.8 0.8 0.7 59.8 377
97.9 98.4 0.5 0.4 63.7 133
--------------------------------------------------------------------
BC-255 (40.8m) No Significant Values
--------------------------------------------------------------------
BC-256 (30.6m) 9.0 10.3 1.4 1.1 13.7 79
--------------------------------------------------------------------
BC-257 (98.8m) No Significant Values
--------------------------------------------------------------------
BC-258 (100.0m) 14.0 15.1 1.1 1.0 7.6 67
--------------------------------------------------------------------
BC-259 (89.8m) 1.4 2.4 1.0 0.9 112.0 885
--------------------------------------------------------------------
BC-260 (101.8m) 8.4 8.8 0.4 0.4 70.6 599
--------------------------------------------------------------------
BC-261 (86.4m) No Significant Values
--------------------------------------------------------------------
BC-262 (91.2m) No Significant Values
--------------------------------------------------------------------
BC-263 (40.6m) 0.5 1.2 0.7 0.6 46.2 233
--------------------------------------------------------------------
BC-264 (60.6m) 46.4 47.8 1.3 1.0 68.6 112
BC-265 (107.4m) 82.5 82.7 0.2 0.2 40.8 69
--------------------------------------------------------------------
BC-266 (90.0m) No Significant Values
--------------------------------------------------------------------
BC-267 (100.1m) No Significant Values
--------------------------------------------------------------------
BC-268 (60.2m) 48.3 48.8 0.6 0.5 41.0 31
--------------------------------------------------------------------
BC-269 (89.6m) No Significant Values
--------------------------------------------------------------------
BC-270 (54.0m) 31.7 33.4 1.8 1.5 10.5 22
--------------------------------------------------------------------
BC-271 (70.0m) No Significant Values
--------------------------------------------------------------------
BC-272 (117.0m) 16.4 18.0 1.6 1.5 10.7 186
--------------------------------------------------------------------
BC-273 (120.1m) 27.1 28.5 1.4 1.2 23.1 67
39.2 39.5 0.3 0.3 71.3 560
104.1 104.3 0.3 0.2 111.5 423
--------------------------------------------------------------------
BC-274 (111.0m) No Significant Values
--------------------------------------------------------------------
BC-275 (129.2m) 25.6 28.0 2.5 2.3 67.7 330
Includes: 25.9 27.2 1.3 1.2 125.5 592
--------------------------------------------------------------------
BC-276 (126.2m) 25.6 27.3 1.8 1.7 17.8 107
--------------------------------------------------------------------
BC-277 (140.7m) 29.4 30.6 1.2 1.1 14.4 117
--------------------------------------------------------------------
BC-278 (50.0m) 27.7 30.5 2.9 2.6 12.6 68
Includes: 27.7 28.6 1.0 0.9 21.7 87
--------------------------------------------------------------------
BC-279 (130.4m) No Significant Values
--------------------------------------------------------------------
BC-280 (49.9m) 28.9 30.7 1.8 1.4 8.7 77
Includes: 30.1 30.7 0.6 0.5 18.2 163
BC-281 (60.0m) 38.9 38.9 0.6 24.7 86
--------------------------------------------------------------------
BC-282 (146.8m) 2.0 6.7 4.8 4.6 4.1 30
42.8 51.3 8.5 7.8 29.3 110
Includes: 49.1 50.0 0.9 0.8 89.0 276
and: 50.0 51.3 1.3 1.3 74.9 263
--------------------------------------------------------------------
BC-283 (60.0m) 49.6 50.7 1.1 1.0 28.7 74
--------------------------------------------------------------------
BC-284 (80.0m) 62.7 63.1 0.4 0.3 17.2 83
--------------------------------------------------------------------
BC-285 (149.9m) 3.9 4.9 1.1 1.0 5.2 43
23.1 24.0 0.8 0.7 21.7 45
45.3 47.8 2.6 2.3 12.2 85
Includes: 45.3 46.1 0.8 0.7 29.1 161
--------------------------------------------------------------------
BC-286 (100.1m) 71.9 72.2 0.3 0.3 28.5 137
--------------------------------------------------------------------
BC-287 (77.2m) No Significant Values
--------------------------------------------------------------------
BC-288 (80.4m) 0.0 1.2 1.2 1.1 31.9 112
--------------------------------------------------------------------



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