Lumina Receives Excellent Metallurgical Results for Regalito.

VANCOUVER, British Columbia -- Lumina Copper Corp. (TSX:LCC)(AMEX:LCC) is pleased to announce that it has received a report from SGS Lakefield (Chile) detailing the metallurgical recovery and acid consumption results for the bottle roll test program completed on mineralized material from its Regalito copper property, Chile. The results confirm the leachability estimates from the drill assay results and provide initial insights into operating metallurgical recoveries and acid consumption rates. The copper recoveries on test material, grading above the economic cutoff grade of 0.25% CuT, averaged 89% and 75% of total copper ("CuT") for oxides and supergene sulphides respectively. For the sulphides, net acid consumption rates averaged 12.4 kg/tonne ore. The oxide material, however, generated 0.55 kg/tonne of acid, due to the predominance of chalcanthite, a water-soluble copper sulphate mineral that dissolves quickly and adds acid to leaching systems.

Anthony Floyd, President said, "These preliminary metallurgical results from Regalito are outstanding and fully confirm our view that Regalito will become a major copper leach operation. We will continue leach tests throughout 2005 in order to provide data to all of the mining companies reviewing the property and for a prefeasibility study later in the year."

The bottle roll test program evaluated several different areas, depths, host rock types, and styles of mineralization and alteration in the deposit. The mineralized material tested was obtained from splits of selected 2-meter assay samples from the early stages of the reverse circulation drilling program carried out in 2004. A total of 82 samples were tested, of which 29 oxide and 47 supergene sulphide samples graded above the 0.25% CuT heap leach cutoff. Low-grade samples (less than 0.25% CuT) gave recoveries of interest (59% of CuT) for the dump leach design. The oxide and sulphide test programs operated for 3 and 35 days respectively. The test work showed no deleterious elements in solution that would hinder bacterial leaching or the proposed solvent extraction/electrowinning metallurgical process.

A detailed breakdown of the tests is provided in the following tables:

Summary of Results from Oxide Test Program (material greater
than 0.25%CuT)
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                                      Recovery    Acid Consumption
Lithology             # of samples      (% CuT)      (kg/tonne ore)
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Monzogranite                    14        89.9                -4.8(1)
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Dacite Porphyry                 15        87.8                 3.4
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                                      Recovery
Grade                 # of samples      (% CuT)
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greater than 1% CuT              4        90.7
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plus 0.75% - 1%                  6        94.7
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plus 0.5% - 0.75%                8        86.3
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plus 0.25% - 0.5%               11        86.8
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(1) Negative acid consumption refers to acid generation.


Summary of Results from Sulphide Test Program (material greater
than 0.25% CuT)
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                                     Recovery     Acid Consumption
Lithology             # of samples     (% CuT)       (kg/tonne ore)
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Monzogranite                     7       79.1                 13.3
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Dacite Porphyry                 40       74.5                 12.2
------------------------------------------------------------------

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                                     Recovery         Leachability
Grade                 # of samples     (% CuT)               (CuT%)
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 greater than 1% CuT            11       73.5                 85.0
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plus 0.75% - 1%                  4       73.7                 95.1
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plus 0.5% - 0.75%               14       76.8                 93.4
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plus 0.25% - 0.5%               19       72.7(2)              87.0
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(2) Two of the nineteen samples had substantially lower recoveries
    (27% and 46%) than the recovery ranges observed for the other
    samples. This may be a result of higher quantities of primary
    mineralization (chalcopyrite) in those samples adversely
    affecting their leachability. Excluding these two samples from
    the data set increased the average recovery to 76.9% CuT.

The supergene sulphide test work was inadvertently biased towards samples from the dacite porphyry rock type and therefore the average recovery for the sulphide tests may understate actual recoveries as the distribution of monzogranite and dacite porphyry rock types at Regalito is estimated to be 60% monzogranite and 40% dacite porphyry. Furthermore, acid consumption rates generated from bottle roll testing on fine material are typically two to three times higher than the acid consumption rates that will occur during heap leach operations.

The bottle roll results compare very favourably with metallurgical recovery rates achieved at comparable copper oxide and sulphide leaching operations. The following table provides a list of certain leaching operations and the actual recoveries that have been achieved during the recent past.

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                                      Recovery
Property                  Owner         (% CuT)(3)
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Regalito
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  Oxide                                     89
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  Sulphide                                  75
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El Abra            Phelps Dodge             62
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Cerro Verde        Phelps Dodge             71
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Miami              Phelps Dodge             65
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Morenci            Phelps Dodge             59
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Tyrone             Phelps Dodge             65
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El Tesoro           Antofagasta             78
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Zaldivar            Placer Dome             81
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Quebrada Blanca   Aur Resources             61
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Andacolla         Aur Resources             80
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Cerro Colorado      BHPBilliton             79
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(3) Data derived from information available in the public domain.
    Note: some of the comparable recoveries may include recoveries
    from dump leach operations, which could lower the recovery
    estimate for the operation.

Lumina continues to make excellent progress with the remainder of the metallurgical testing program. The short column (1m height) program is nearing completion, while the tall column (6-8m height) program, which began leaching on April 29, will continue operating for another nine months.

Mr. John Selters, P.Eng., a Qualified Person as defined by National Instrument 43-101, has reviewed and approved the content of this news release.

LUMINA COPPER CORP.

Anthony Floyd, President

CAUTION REGARDING FORWARD LOOKING STATEMENTS: Safe Harbor Statement under the United States Private Securities Litigation Reform Act of 1995: Except for the statements of historical fact contained herein, the information presented constitutes "forward-looking statements" within the meaning of the Private Securities Act of 1995. Such forward-looking statements, including but not limited to those with respect to the price of copper, gold and molybdenum, the timing and amount of future production, metallurgical recoveries, costs of production, reserve and resource determination and reserve conversion rates, involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievement of the Company to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Such factors include, among others, risks relating to the integration of acquisitions, risk relating to international operations, risks relating to joint-venture operations, the actual results of current exploration activities, conclusions of economic evaluations, changes in project and exploration parameters as plans continue to be refined, future prices of copper, gold and molybdenum, as well as those factors discussed in the section entitled "Risk Factors" in the Form 20-F as on file with the Securities and Exchange Commission in Washington, D.C. Although the Company has attempted to identify important factors that could cause actual results to differ materially, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.

Lumina Copper Corp. (TSX:LCC) (AMEX:LCC)