International Minerals Announces Positive Preliminary Economic Assessment and Increased Resource Estimate at Inmaculada Project, Peru

International Minerals Corporation (TSX: IMZ)(Zurich: IMZ) is pleased to
announce the results of an independent Preliminary Economic Assessment
('Scoping study?) and an updated, increased mineral resource estimate
for the Angela Vein deposit at the Inmaculada gold-silver project
('Inmaculada?) in southern Peru. IMZ controls a 70% interest (Hochschild
Mining 30%) in Inmaculada with a present 51% interest in direct
ownership and currently earning the 70% interest by completing a
feasibility study before September 2013 and by issuing 200,000 IMZ
shares to Hochschild over a 5-year period commencing February 2011. IMZ
intends to fast-track the feasibility study and complete it by the end
of 2011.

Highlights of Scoping Study (base case
using $1,000 per ounce ('/oz?) gold and $17/oz silver and a 60:1
silver-to-gold equivalency ratio. All currency amounts in US dollars):

• 
  Conceptual mine production (after 5% mining loss and 20% mining
  dilution): 8.0 million tonnes ('Mt?) at an average grade of 3.8 grams
  per tonne ('g/t?) gold and 137 g/t silver or 6.1 g/t gold equivalent.
  
• 
  Recovered ounces ('ozs?): 858,000 ozs gold and 29.3 million ozs silver
  or approximately 1.35 million ounces of gold equivalent (based on
  metallurgical recoveries of 88% for gold and 83% for silver).
  
• 
  Pre-tax cash flows: $660 million non-discounted, $434 million at a 5%
  discount rate and $286 million at a 10% discount rate.
  
• 
  Pre-tax Internal Rate of Return (?IRR?): 41%.
  
• 
  Total cash operating cost per tonne: $52.
  
• 
  Total cash operating cost per oz:
  
  
  • 
    Basis gold with silver credited as a by-product: negative $94 per
    oz of gold (indicating that silver by-product revenue is great
    than the total cash operating cost.)
    
  • 
    Basis gold equivalent: $311 per oz of gold equivalent.
    

• 
  Initial Capital: $168 million (including $32.9 million in contingency).
  
• 
  Total cash operating cost per oz, including capital:
  
  
  • 
    Basis gold with silver credited as a by-product: $231 per oz.
    
  • 
    Basis gold equivalent: $517 per oz
    
• 
  3,000 tonnes per day ('tpd?) underground mine using a long hole
  stoping mining method and conventional recovery process by flotation
  to produce a saleable gold-silver concentrate.
  

Highlights of Independent Updated
Resource Estimate (100% project basis):

• Measured and Indicated ('M&I?) Mineral Resources of 3.8 Mt
  at an average grade of 4.3 g/t gold and 129 g/t silver respectively,
  containing approximately 532,000 ounces of gold and 15.8 million
  ounces of silver or 796,000 ounces of gold equivalent (basis 3 g/t
  gold equivalent cut-off grade).
  

This new M&I resourceestimate represents a 245%
increase in gold ounces and 225% increase in silver ounces compared
to the previous IMZ resource estimate (see news release dated February
3, 2010). In addition, the average gold and silver grades in the M&I
categories increased by 10% and 6% respectively.

• Inferred Mineral Resources of 4.4 Mt at an average grade of 4.6
  g/t gold and 200 g/t silver respectively containing approximately
  645,000 ounces of gold and 28.3 million ounces of silver or 1,116,000
  ounces gold equivalent (basis 3 g/t gold equivalent cut-off grade).
  

This new inferred resource estimate represents a 26% increase in gold
ounces and 28% increase in silver ounces compared to the February 2010
resource estimate In addition, the average gold and silver grades in the
Inferred category increased by 35% and 36% respectively.

Scoping Study Details

Results of the Scoping study for the Inmaculada Project indicate that at
base case gold and silver prices of $1,000/oz and $17/oz respectively
and a 3,000 tpd throughput, an underground mining project could return a
pre-tax non-discounted cash flow of approximately $660 million based on
the Scoping study conceptual diluted mine production of 8.0 Mt at a
grade of 3.8 g/t gold and 137 g/t silver.

The independent Scoping study was overseen by P & E Mining Consultants
Inc. of Brampton, Ontario Canada ('P&E?), with Golder Associates Perú
S.A. ('Golder?) responsible for the tailing disposal facility and fresh
water supply studies and FSS Canada Consultants Inc. ('FSS?) responsible
for the updated resource estimate.

The results of the Scoping study are shown below in Table 1, with
sensitivities to metal prices shown in Table 2.

Table 1. Inmaculada, Angela Vein
Scoping Study (100% Project Basis, all in US Dollars)

1) This Preliminary Economic Assessment or Scoping study is preliminary
in nature, in that it includes inferred mineral resources that are
considered too speculative geologically to have the economic
considerations applied to them that would enable them to be categorized
as mineral reserves, and there is no certainty that the results of the
preliminary economic assessment study will be realized and actual
results may vary substantially.

2) Initial Capital includes $32.9 million in contingency allowance.
Costs are based on Q3 2010 estimates and no escalation factors have been
applied. Value added tax has not been included in the cost estimates.

3) Total Cash Operating costs include smelting and refining and Peruvian
Government royalties, but do not include employee profit sharing or
depreciation, depletion or amortization.

4) Total Cash Costs per ounce of gold equivalent are calculated using a
silver-to-gold ratio of 60:1.

5) By-product accounting subtracts the revenue generated by silver from
the operating costs as a credit to determine the cost per ounce of gold.

6) Annual and life-of-mine production figures are after 5% mining
losses, 20% mining dilution and the respective metallurgical recoveries
for gold and silver.

7) Mineral resources that are not mineral reserves do not have
demonstrated economic viability.

Table 2. Inmaculada, Angela Vein
Sensitivity Analyses (100% Project Basis, all in US Dollars, base case
in bold and highlighted)

1) Cash flow and NPV′s are all shown pre-tax, but do include Peruvian
government royalties and smelter and transportation charges. Value added
tax (generally recoverable in Peru) was not included in the cash flows.

Mining

The mine design concept for Inmaculada is to utilize the long hole
stoping mining method. The Angela Vein deposit is well suited for this
method with good continuity of mineralization along strike and average
vein widths of approximately six meters. A main development decline will
be driven in the footwall of the vein(s) and the mining blocks will be
defined and accessed from a series of spiral ramps driven off the main
decline. A majority of the mineralization to be mined is above the main
development decline, allowing for gravity transport to the decline for
trucking to the process plant. Paste backfill of the mined out stopes is
planned to minimize mining recovery losses. Sub-level spacing is 25m,
with an assumed 5% mine loss and 20% mining dilution.

Processing

The base case processing plan for Inmaculada project envisages crushing
and grinding, followed by flotation to generate a saleable gold-silver
concentrate (similar to the recovery process at IMZ′s 40%-owned
Pallancata mine located 25km to the North). The Angela Vein
mineralization is amenable to other industry-standard recovery methods,
but currently the flotation option provides the best project economics.

Mineral Resource Estimate Details

Based on drill results received up to a cut-off date of May 15^th,
2010 (drill hole INMA 139), an updated mineral resource estimate was
calculated by FSS Canada, an independent consulting firm. This new
estimate was used as the basis for the Scoping study.

The updated resource, as shown in Table 3 and summarized below (on a
100% project basis) comprises:

• Measured and Indicated Resources: 3.8 Mt at an average grade of
  4.3 g/t gold and 129 g/t silver containing approximately 532,000
  ounces of gold and 15.8 million ounces of silver.
  
• Inferred Resources of 4.4 Mt at an average grade of 4.6 g/t
  gold and 200 g/t silver containing approximately 645,000 ounces of
  gold and 28.3 million ounces of silver.
  

This updated resource estimate, which includes Measured resources for
the first time, represents a significant increase in both the confidence
level of the resource estimate and the overall gold and silver content
of the Angela Vein deposit from the previously-reported,
independently-calculated, Indicated and Inferred mineral resource
estimate, as discussed in the Highlight section of this news release.

The resource estimate is reported at a cut-off grade of 3 g/t gold
equivalent (using a silver to gold ratio of 60:1), which approximates
the cut-off grade for the underground mining and flotation process
option selected for Inmaculada, using a base-case gold price of US$1,000
per ounce. Because the cut-off grade is a factor of operating costs,
metallurgical recoveries and gold price, it is possible that a lower or
higher cut-off grade could be applied in the future.

Table 3.Angela
Vein, Inmaculada Project ? Mineral Resource Estimate at a cut-off grade
of 3 g/t gold equivalent (as of September 9, 2010 at US$1,000/oz gold
and $17/oz silver)

1) Resources are shown on a 100% project basis. IMZ controls a 70%
interest (Hochschild Mining 30%) with a current 51% ownership and is
earning a 70% interest by completing a feasibility study before
September 2013 and issuing to Hochschild 200,000 IMZ shares.

2) Numbers are rounded to reflect the precision of a resource estimate.

3) The estimated mineral resources are not mineral reserves and do not
have demonstrated economic viability.

4) To limit the influence of individual high-grade samples, grade
cutting was used. Gold assay grades were capped at 100 g/t and silver
grades were capped at 1,500 g/t.

5) Average dry bulk densities of 2.51 tonnes per cubic meter ('t/m^3?)
were used for all mineralized rocks.

6) The grades were interpolated using 'Ordinary Kriging? estimation
technique.

7) Descriptions of parameters to determine 'Measured?, 'Indicated? and
'Inferred? resources are provided below.

8) The contained metal estimates remain subject to factors such as
mining dilution and process recovery losses.

9) The mineral resources in this press release were estimated using the
Canadian Institute of Mining, Metallurgy and Petroleum (CIM), CIM
Standards on Mineral Resources and Reserves, Definitions and Guidelines
prepared by the CIM Standing Committee on Reserve Definitions and
adopted by CIM Council December 11, 2005.

The mineral resources were estimated based on IMZ′s previously-released
assay results from 139 core drill holes totaling approximately 48,513m
over a strike length of 2 km. These mineral resources were classified in
accordance with CIM guidelines by FSS′s Qualified Person, R. Mohan
Srivastava (P.Geo.), and the estimate has an effective date of September
9, 2010.

Ordinary kriging was used to interpolate gold grades for four separate
sub-domains that may intermix within each block (block size is 10 meters
('m?) long by 2m wide by 10m high). The four sub-domains were defined by
geological sectional interpretation. The grades of each sub-domain were
interpolated separately, using only the nearby data from the same
sub-domain, and the final block grade was calculated by taking the
proportion and density-weighted average of the grades from each of the
sub-domains.

Resources were classified according to the number of nearby drill holes,
their proximity to the block being estimated, and their spatial
arrangement around the block. Blocks were classified as Measured
Resources if they were estimated by data within the range of the
variogram in at least four of eight octants, and with a sample within
25m (1/3 the range of the variogram) of the block center. Blocks were
classified as Indicated Resources if they were estimated by data within
the range of the variogram from at least two drill holes in at least
three of eight octants, and with a sample within 50m (2/3 the range of
the variogram) of the block center. Blocks were classified as Inferred
Resources if they had data within the range of the variogram but could
not be classified as Measured or Indicated Resources.

Over 99% of all of the assays within the Angela Vein domains were
verified against the original assay certificates provided by the SGS
laboratory. Eight Angela Vein assays from one of the original
exploration holes (drilled by Hochschild) could not be checked against
original records and were checked, instead, against previously tabulated
values.

General

The technical information reported in this news release was reviewed and
approved by IMZ′s Qualified Person, VP of Corporate Development, Nick
Appleyard and Eugene Puritch P.Eng. President of P&E Mining Consultants
Inc.

A NI 43-101 Technical Report will be filed by IMZ on SEDAR within 45
days of the date of this news release.

Hochschild Mining does not accept any responsibility for the adequacy
or inadequacy of the disclosure made in this news release and any
responsibility is hereby disclaimed in all respects.

About International Minerals

International Minerals is a silver-gold producer and developer with
silver and gold production from its 40%-owned Pallancata Mine in Peru,
one of the top-10 primary silver mines in the world. Production of
approximately 10 million ounces of silver and 33,000 ounces of gold (on
a 100% project basis) is estimated by IMZ in calendar year 2010.

In addition to the Pallancata Mine, IMZ also controls a 70% interest in
the Inmaculada gold-silver project in Peru and majority or 100%
ownership interests in development stage gold projects in Nevada
(Goldfield and Converse) and Ecuador (Rio Blanco and Gaby). IMZ also
owns a 3% net smelter return ('NSR?) royalty from Barrick Gold′s Ruby
Hill gold mine in Nevada, which produced approximately 100,000 gold
ounces in 2009.

IMZ is listed on the Toronto Stock Exchange (since 1994) and the Swiss
Stock Exchange (since 2002).

Internet Site: http://www.intlminerals.com

Cautionary Statement:

Some of the statements contained in this release are 'forward-looking
statements? within the meaning of Canadian securities law requirements.
Such forward-looking statements involve known and unknown risks,
uncertainties and other factors that may cause our actual results,
performance or achievements to differ materially from the anticipated
results, performance or achievements expressed or implied by such
forward-looking statements. Forward-looking statements in this release
include statements regardingestimates of capital and operating
costs; economic returns; timing and significance of future cash flows
and revenue from the project; timing and outcome of any feasibility
study; and timing and scale of production and processing; and resource
estimates. Factors that could cause actual results to differ materially
from anticipated results include risks and uncertainties such as: risks
relating to estimates of production and processing rates; risks relating
to estimates of mineral resources; risks relating to capital and