Saturday, September 26, 2026
MiningNewsTerminal
Saturday, September 26, 2026 Admin

IMG.TO ·

Iamgold Achieves 23% Annual Increase IN Reserves; Reports 2018 Reserves of 17.9 Million Ounces and Measured and Indicated Resources of 27.9 Million Ounces

Resource Estimates

NEWS RELEASE

TSX: IMG NYSE: IAG

IAMGOLD ACHIEVES 23% ANNUAL INCREASE IN RESERVES;

REPORTS 2018 RESERVES OF 17.9 MILLION OUNCES

AND MEASURED AND INDICATED RESOURCES OF 27.9 MILLION OUNCES

All dollar amounts are in U.S. dollars unless otherwise indicated.

Measured and Indicated Resource Estimates are quoted Inclusive of Mineral Reserves for all sites and projects

Toronto, Ontario, February 19, 2019 – IAMGOLD Corporation (“IAMGOLD” or the “Company”) today

announced its 2018 year-end mineral reserve and resource statement. (See attached table for more

details.)

Total attributable Proven and Probable gold Reserves increased by 23% to 17.9 million ounces at the end of

2018 from 14.5 million ounces of gold at the end of 2017. The addition of 3.4 million ounces was primarily

due to the previously announced conversion of Resources to Reserves at Saramacca in Suriname, Côté

Gold in Ontario, and at Boto Gold in eastern Senegal, West Africa, coupled with the previously

announced Reserve increase at the Essakane Gold Mine following the Pre-Feasibility Study. These

increases were partially offset by depletion during the year given the Company's attributable gold

production of 882,000 ounces. There was no change in the $1,200 per ounce gold price assumption for

estimating Mineral Reserves at the Company’s owned and operated mines and development projects.

Total attributable Measured and Indicated gold Resources (inclusive of Reserves) increased overall by

13% or 3.1 million ounces to 27.9 million ounces of gold at the end of 2018. Total attributable Inferred gold

Resources remained at a similar level to the prior year at 8.7 million ounces at the end of 2018. There

were no changes in the gold price assumptions for estimating mineral resources at Essakane, Rosebel,

and resource-stage projects ($1,500 per ounce of gold) or at Westwood ($1,200 per ounce of gold).

Steve Letwin, President and CEO of IAMGOLD, commented, “In 2018, we continued our work to increase

reserve ounces at the Company, adding another 3.4 million ounces on top of the 6.7 million ounces we

added in 2017, on an attributable basis. Over the last two years, we have increased our attributable

reserves by 129 percent, net of mine depletion. Once again, each of our owner-operated mines

experienced a year over year increase in reserves, net of depletion, underscoring the strength of our core

assets. At Rosebel, we declared initial reserves at Saramacca of 1.0 million attributable ounces while

more than replacing depletion on the Rosebel concession. At Essakane, with the Prefeasibility study

completed during 2017, we were able to add 0.9 million attributable ounces, after depletion in reserves.

With the feasibility study completed at Côté Gold, we converted 3.2 million ounces to the Proven category

while also adding 0.9 million ounces to the reserve base, on an attributable basis.”

Mr. Letwin continued, “In 2019, we plan to continue our reserve and resource growth through both

brownfield and greenfield exploration programs. At Rosebel, our goal is to add resources along the

Saramacca-Brokolonko trend and test priority targets on the Rosebel concession. At Essakane, our 24

kilometre drill program is intended to support the ongoing heap leach and CIL optimization feasibility

study, while we also continue to explore high priority regional targets to identify additional satellite

resources. At Westwood, we continue to work on resource conversion and expansion, with another 65

kilometres of drilling planned for 2019. At our development projects at Côté Gold and Boto Gold, we will

continue to advance exploration programs targeting resource expansions as well as new discoveries on

adjacent concessions. Finally, at our greenfield projects, we will continue to advance our industry-leading

pipeline, including the completion of a maiden resource estimate at Nelligan in Quebec.”

Summaries of the changes in the Reserves and Resources estimate and 2019 development plans for

each of the key assets are provided below.

page 2 of 7

Rosebel Gold Mine, Suriname: As announced on September 23, 2018, Rosebel was able declare

increases in Reserves, before including the Saramacca satellite deposit. Incorporating those additions

and mine depletion since that declaration date, Rosebel has realized a net, year-on-year increase in

attributable Reserves of 0.3 million ounces or 8% to 3.6 million ounces, which was largely the result of

upgrading resources at the Koolhoven deposit to reserves. Attributable Measured and Indicated

Resources decreased 0.7 million ounces or 8% and attributable Inferred Resources decreased by 0.9

million ounces to 1.7 million ounces compared to the prior year as a result of revised deposit models and

the impact of changes in the cost models.

Saramacca Gold Project, Suriname: On September 23, 2018, a maiden Reserve was declared for the

Saramacca deposit, 25 km southwest of the Rosebel Gold Mine. Attributable Probable Reserves were

estimated to be 1.0 million ounces. Attributable Indicated Resources of 1.2 million ounces and Inferred

Resources of 182,000 ounces. In 2019, approximately 45 kilometres of diamond and reverse circulation

drilling are planned to expand resources and test priority exploration targets on the Rosebel concession

and along the Saramacca-Brokolonko trend.

Essakane Gold Mine, Burkina Faso: On June 5, 2018, Essakane completed a Pre-feasibility Study

incorporating heap leach processing methods in addition to the existing CIL process. As a result,

attributable Reserves for 2018 increased by 29%, net of depletion, to 3.9 million ounces versus the prior

year. Attributable Indicated Resources increased by 917,000 ounces or 24% to 4.8 million ounces and

attributable Inferred Resources increased by 76,000 ounces to 423,000 ounces. In the first half of 2019,

Essakane expects to complete a Feasibility Study on the heap leach scenario which contemplates

processing heap leach reserves subsequent to the existing CIL operation. On December 12, 2018, the

Company announced a maiden Resource estimate for the Gossey satellite deposit, 15 kilometers to the

northwest of the Essakane processing plant, which includes attributable Indicated Resources of 262,000

ounces and attributable Inferred Resources of 77,000 ounces.

Westwood Gold Mine, Canada: A net increase in Reserves of 35,000 ounces or 3% to 1.2 million

ounces converted from resources, after depletion. Measured and Indicated Resources increased by

73,000 ounces or 5% to 1.5 million ounces. Inferred Resources declined by 158,000 ounces to 1.7 million

ounces. Westwood is planning a further 65 kilometres of drilling during 2019 to continue building

reserves through conversion of resources.

Sadiola Gold Mine, Mali: At Sadiola, there was a net decrease year-on-year in attributable Reserves of

67,000 ounces or 4% to 1.6 million ounces due to depletion. Attributable Measured and Indicated

Resources decreased by 60,000 ounces to 2.8 million ounces. Inferred Resources remained unchanged

at 0.4 million ounces. No significant exploration activity is planned for Sadiola in 2019 as we continue to

work to reach an agreement with the Government of Mali for the path forward for the Sadiola Sulphide

Project.

Côté Gold Project, Canada: On November 1, 2018, the Company announced positive results from a

Feasibility Study. Attributable Proven and Probable Reserves increased by 0.9 million ounces to 4.7

million ounces when compared to the prior year. As part of the successful resource conversion,

attributable Measured Resources of 3.4 million ounces were declared, with combined attributable

Measured and Indicated resources increasing by 1.3 million ounces to 6.5 million ounces. In addition,

attributable Inferred Resources were up 0.8 million ounces, or 97%, to 1.6 million ounces.

Boto Gold Project, Senegal: On October 22, 2018, the Company announced positive results from the

Feasibility Study. For 2018, reserves are shown as 90% attributable to IAMGOLD with the remaining

portion being attributed to the Government of Senegal upon grant of a mining concession. In 2018,

attributable Probable Reserves increased 0.3 million ounces to 1.7 million ounces. Attributable Indicated

Resources increased by 0.3 million ounces to 2.3 million ounces while attributable Inferred Resources

decreased by 0.5 million ounces to 130,000 ounces as a result of resource upgrade to an indicated

category.

page 3 of 7

Advance Exploration Projects: At Diakha-Siribaya in Mali, Indicated Resources increased by 539,000

ounces to 668,000, and Inferred Resources increased by 34,000 to 1.1 million ounces. Additionally, initial

Resource estimates were declared at Monster Lake in Canada, including attributable Inferred Resources

of 217,000 ounces, and at Eastern Borosi in Nicaragua, including attributable Inferred Resources of

414,000 ounces. An initial resource estimate at Nelligan in Canada is expected during 2019.

Forward Looking Statement

This news release contains forward-looking statements. All statements, other than of historical fact, that address

activities, events or developments that the Company believes, expects or anticipates will or may occur in the future

(including, without limitation, statements regarding expected, estimated or planned gold production, cash costs,

margin expansion, capital expenditures and exploration expenditures and statements regarding the estimation of

mineral resources, exploration results, potential mineralization, potential mineral resources and mineral reserves) are

forward-looking statements. Forward-looking statements are generally identifiable by use of the words “may”, “will”,

“should”, “continue”, “expect”, “expected”, “anticipate”, “estimate”, “believe”, “intend”, “plan” or “project” or the

negative of these words or other variations on these words or comparable terminology. Forward-looking statements

are subject to a number of risks and uncertainties, many of which are beyond the Company’s ability to control or

predict, that may cause the actual results of the Company to differ materially from those discussed in the forward-

looking statements. Factors that could cause actual results or events to differ materially from current expectations

include, among other things, without limitation, failure to meet expected, estimated or planned gold production, cash

costs, margin expansion, capital expenditures and exploration expenditures and failure to establish estimated mineral

resources, the possibility that future exploration results will not be consistent with the Company's expectations,

changes in world gold markets and other risks disclosed in IAMGOLD’s most recent Form 40-F/Annual Information

Form on file with the United States Securities and Exchange Commission and Canadian provincial securities

regulatory authorities. Any forward-looking statement speaks only as of the date on which it is made and, except as

may be required by applicable securities laws, the Company disclaims any intent or obligation to update any forward-

looking statement.

Technical Information and Qualified Person/Quality Control Notes

The mineral resource estimates contained in this news release have been prepared in accordance with National

Instrument 43-101 Standards of Disclosure for Mineral Projects (“NI 43-101”). The “Qualified Person” responsible for

the review and approval of all mineral resource and reserve estimates for IAMGOLD contained herein is Lise

Chenard, Eng., Director, Mining Geology. Lise has worked in the mining industry for more than 35 years, mainly in

operations, project development and consulting. She joined IAMGOLD in April 2013 and acquired her knowledge of

the Company’s operations and projects through site visits, information reviews and ongoing communication and

oversight of mine site technical service teams or consultants responsible for resource and reserve modeling and

estimation.

She is considered a “Qualified Person” for the purposes of NI 43-101 with respect to the mineralization being reported

on. The technical information has been included herein with the consent and prior review of the above noted Qualified

Person. The Qualified person has verified the data disclosed, and data underlying the information or opinions

contained herein.

The information in this news release was reviewed and approved by Craig MacDougall, P.Geo., Senior Vice

President, Exploration for IAMGOLD. Mr. MacDougall is a Qualified Person as defined by National Instrument 43-

101.

Notes to Investors Regarding the Use of Resources

Cautionary Note to Investors Concerning Estimates of Measured and Indicated Resources

This news release uses the terms "measured resources" and "indicated resources". We advise investors that while

those terms are recognized and required by Canadian regulations, the United States Securities and Exchange

Commission (the “SEC”) does not recognize them. Investors are cautioned not to assume that any part or all of

mineral deposits in these categories will ever be converted into reserves.

Cautionary Note to Investors Concerning Estimates of Inferred Resources

This news release also uses the term "inferred resources". We advise investors that while this term is recognized and

required by Canadian regulations, the SEC does not recognize it. "Inferred resources" have a great amount of

uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. It cannot be

assumed that all or any part of an inferred mineral resource will ever be upgraded to a higher category. Under

Canadian rules, estimates of inferred mineral resources may not form the basis of feasibility or pre-feasibility studies,

except in rare cases. Investors are cautioned not to assume that part or all of an inferred resource exists, or is

economically or legally mineable.

page 4 of 7

Scientific and Technical Disclosure

IAMGOLD is reporting mineral resource and reserve estimates in accordance with the CIM guidelines for the

estimation, classification and reporting of resources and reserves.

Note: Mineral reserves and mineral resources for IAMGOLD’s gold mines for the 2018 year-end statement were

estimated using a $1,200 per ounce gold price (unless otherwise indicated in the notes in Table 1) for mineral

reserves and a $1,500 per ounce price for mineral resources (unless otherwise indicated in the notes in Table 1).

For open pit operations, gold resources are constrained within an economic pit shell.

Cautionary Note to U.S. Investors

The SEC limits disclosure for U.S. reporting purposes to mineral deposits that a company can economically and

legally extract or produce. IAMGOLD uses certain terms in this news release, such as "measured," "indicated," or

"inferred," which may not be consistent with the reserve definitions established by the SEC. U.S. investors are urged

to consider closely the disclosure in the IAMGOLD Annual Reports on Forms 40-F. You can review and obtain copies

of these filings from the SEC's website at http://www.sec.gov/edgar.shtml or by contacting the Investor Relations

department.

The Canadian Securities Administrators' National Instrument 43-101 ("NI 43-101") requires mining companies to

disclose reserves and resources using the subcategories of "proven" reserves, "probable" reserves, "measured"

resources, "indicated" resources and "inferred" resources. Mineral resources that are not mineral reserves do not

demonstrate economic viability.

A mineral reserve is the economically mineable part of a measured or indicated mineral resource demonstrated by at

least a preliminary feasibility study. This study must include adequate information on mining, processing,

metallurgical, economic and other relevant factors that demonstrate, at the time of reporting, that economic extraction

can be justified. A mineral reserve includes diluting materials and allows for losses that may occur when the material

is mined. A proven mineral reserve is the economically mineable part of a measured mineral resource demonstrated

by at least a preliminary feasibility study. A probable mineral reserve is the economically mineable part of an

indicated, and in some circumstances, a measured mineral resource demonstrated by at least a preliminary feasibility

study.

A mineral resource is a concentration or occurrence of natural, solid, inorganic material, or natural, solid fossilized

organic material including base and precious metals in or on the Earth's crust in such form and quantity and of such a

grade or quality that it has reasonable prospects for economic extraction. The location, quantity, grade, geological

characteristics and continuity of a mineral resource are known, estimated or interpreted from specific geological

evidence and knowledge. A measured mineral resource is that part of a mineral resource for which quantity, grade or

quality, densities, shape and physical characteristics are so well established that they can be estimated with

confidence sufficient to allow the appropriate application of technical and economic parameters, to support production

planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable

exploration, sampling and testing information gathered through appropriate techniques from locations such as

outcrops, trenches, pits, workings and drill holes that are spaced closely enough to confirm both geological and grade

continuity. An indicated mineral resource is that part of a mineral resource for which quantity, grade or quality,

densities, shape and physical characteristics can be estimated with a level of confidence sufficient to allow the

appropriate application of technical and economic parameters, to support mine planning and evaluation of the

economic viability of the deposit. The estimate is based on detailed and reliable exploration and testing information

gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that

are spaced closely enough for geological and grade continuity to be reasonably assumed. An inferred mineral

resource is that part of a mineral resource for which quantity and grade or quality can be estimated on the basis of

geological evidence and limited sampling and reasonably assumed, but not verified, geological and grade continuity.

The estimate is based on limited information and sampling gathered through appropriate techniques from locations

such as outcrops, trenches, pits, workings and drill holes. Mineral resources which are not mineral reserves do not

have demonstrated economic viability.

Investors are cautioned not to assume that part or all of an inferred resource exists, or is economically or

legally mineable.

A feasibility study is a comprehensive technical and economic study of the selected development option for a mineral

project that includes appropriately detailed assessments of realistically assumed mining, processing, metallurgical,

economic, marketing, legal, environmental, social and governmental considerations together with any other relevant

operational factors and detailed financial analysis, that are necessary to demonstrate at the time of reporting that

extraction is reasonably justified (economically mineable). The results of the study may reasonably serve as the

basis for a final decision by a proponent or financial institution to proceed with, or finance, the development of the

project. The confidence level of the study will be higher than that of a Pre-Feasibility Study.

A Pre-Feasibility Study is a comprehensive study of a range of options for the technical and economic viability of a

mineral project that has advanced to a stage where a preferred mining method, in the case of underground mining, or

page 5 of 7

the pit configuration, in the case of an open pit, is established and an effective method of mineral processing is

determined. It includes a financial analysis based on reasonable assumptions on mining, processing, metallurgical,

economic, marketing, legal, environmental, social and governmental considerations and the evaluation of any other

relevant factors which are sufficient for a qualified person, acting reasonably, to determine if all or part of the Mineral

Resource may be classified as a Mineral Reserve.

About IAMGOLD

IAMGOLD (www.iamgold.com) is a mid-tier mining company with four operating gold mines on three

continents. A solid base of strategic assets in North and South America and West Africa is complemented

by development and exploration projects and continued assessment of accretive acquisition

opportunities. IAMGOLD is in a strong financial position with extensive management and oper ational

expertise.

For further information please contact:

Indi Gopinathan, Investor Relations Lead, IAMGOLD Corporation

Tel: (416) 360-4743 Mobile: (416) 388-6883

Martin Dumont, Senior Analyst Investor Relations, IAMGOLD Corporation

Tel: (416) 933-5783 Mobile: (647) 967-9942

IAMGOLD Corporation Toll-free: 1 888 464-9999 [email protected]

Mineral Reserves and Resources of Gold Operations as of December 31, 201 8(1)(2)(3)(4)(5)(6)(7)(8)

Measured and Indicated Resources are inclusive of Proven and Probable Reserves.

page 6 of 7

Tonnes

(000s)

Grade

(g/t)

Ounces Contained

(000s)

Attributable Contained

Ounces (000s)

Rosebel(3), Suriname (95%)

Proven Reserves 29,776 0.6 587 558

Probable Reserves 100,583 1.0 3,208 3,048

Subtotal 130,359 0.9 3,795 3,606

Measured Resources 35,645 0.6 711 675

Indicated Resources 256,835 0.9 7,683 7,299

Inferred Resources 64,770 0.9 1,793 1,703

Saramacca(3), Suriname (66.5%)

Probable Reserves 26,549 1.8 1,542 1,025

Subtotal 26,549 1.8 1,542 1,025

Indicated Resources 27,938 2.0 1,763 1,172

Inferred Resources 11,825 0.7 273 182

Essakane(3), Burkina Faso (90%)

Probable Reserves 148,812 0.9 4,380 3,942

Subtotal 148,812 0.9 4,380 3,942

Indicated Resources 173,041 1.0 5,287 4,759

Inferred Resources 13,811 1.1 470 423

Gossey(4), Burkina Faso (90%)

Indicated Resources 10,454 0.9 291 262

Inferred Resources 2,939 0.9 85 77

Westwood(5), Canada (100%)

Proven Reserves 1,317 7.9 336 336

Probable Reserves 3,627 7.5 875 875

Subtotal 4,944 7.6 1,211 1,211

Measured Resources 1,007 11.9 385 385

Indicated Resources 3,169 10.8 1,101 1,101

Inferred Resources 5,494 9.5 1,680 1,680

Sadiola(6), Mali (41%)

Proven Reserves 118 1.7 6 3

Probable Reserves 63,674 1.9 3,971 1,628

Subtotal 63,792 1.9 3,978 1,631

Measured Resources 118 1.7 6 3

Indicated Resources 117,647 1.8 6,904 2,831

Inferred Resources 17,643 1.7 956 392

Côté Gold(3), Canada (64.75%)

Proven Reserves 153,700 1.0 4,640 3,004

Probable Reserves 79,300 0.9 2,644 1,712

Subtotal 233,000 1.0 7,284 4,716

Measured Resources 171,900 1.0 5,310 3,438

Indicated Resources 183,500 0.8 4,660 3,017

Inferred Resources 112,800 0.7 2,430 1,573

Boto Gold(3), Senegal (90%)

Probable Reserves 35,060 1.7 1,926 1,733

Subtotal 35,060 1.7 1,926 1,733

Indicated Resources 48,045 1.6 2,487 2,238

Inferred Resources 2,483 1.8 144 130

Monster Lake, Canada (50%)

Inferred Resources 1,110 12.1 433 217

Eastern Borosi(7), Nicaragua (51%)

Inferred Resources 4,418 5.7 812 414

Pitangui(4), Brazil (100%)

Inferred Resources 5,365 4.7 819 819

Diakha-Siribaya(4), Mali (90%)

Indicated Resources 18,031 1.3 744 669

Inferred Resources 23,179 1.6 1,176 1,058

TOTAL(8)

Proven & Probable Reserves 642,516 1.2 24,116 17,864

Measured and Indicated Resources 1,047,330 1.1 37,333 27,850

Inferred Resources 265,837 1.3 11,071 8,668

page 7 of 7

Notes:

(1) In mining operations, measured and indicated resources that are not mineral reserves are considered uneconomic at the price used for reserve estimations but are

deemed to have a reasonable prospect of economic extraction.

(2) Although “measured resources”, “indicated resources” and “inferred resources” are categories of mineralization that are recog nized and required to be disclosed under

Canadian regulations, the SEC does not recognize them. Disclosure of contained ounces is permitted under Canadian regulation s; however, the SEC generally permits

resources to be reported only as in place tonnage and gr ade. See “Cautionary Note to U.S. Investors Regarding Disclosure of Mineral Reserve and Mineral Resource

Estimates”.

(3) Rosebel, Saramacca, Essakane, Côté Gold, and Boto Gold mineral reserves have been estimated as of December 31, 201 8 using a $1,200/oz gold price and mineral

resources have been estimated as of December 31, 201 8 using a $1,500/oz gold price and have been estimated in accordance with NI 43 -101.

(4) Gossey, Monster Lake, Pitangui, and Diakha-Siribaya mineral resources have been estimated as of December 31, 2018 using a $1,500/oz gold price and have been

estimated in accordance with NI 43-101.

(5) Westwood mineral reserves have been estimated as of December 31, 201 8 using a $1,200/oz gold price and mineral resources have been estimated as o f December 31,

2018 using a 5.5 g/t gold cut-off over a minimum width of 2.4 metres and have been estimated in accordance with NI 43-101.

(6) Mineral reserves at Sadiola have been estimated as of December 31, 201 8 using an average of $1,200/oz gold price and mineral resources have been estimated as of

December 31, 2018 using a $1,400/oz gold price and have been estimated in accordance with the JORC code.

(7) Eastern Borosi mineral resources are disclosed as gold equivalent ounces calculated using the formula: AuEq (g/t) = Au (g/t) + Ag (g/t) / 101.8; and have been estimated

as of December 31, 2018 using a $1,500/oz gold price, and a $23/oz silver price and in accordance with NI 43-101. Underground resources are estimating using a cut -off

grade of 2.0g/t gold equivalent with a minimum width of 2.4m and open pit resources are estimated using a cut-off grade of 0.42 g/t gold equivalent over a 3.0m minimum

width.

(8) Due to rounding, numbers presented throughout this document may not add up precisely to the totals.

The Company’s reserve estimate is comprised of in-place material, i.e., contained ounces of gold and metallurgical recovery factors must

be taken into account in order to assess and quantify the recoverable material.

There are numerous parameters inherent in estimating proven and probable mineral reserves, including many factors beyond the

Company’s control. The estimation of reserves is a subjective proce ss, and the accuracy of any reserve estimate is a function of the

quality of available data and of engineering and geological interpretation and judgment. Results from drilling, testing and p roduction, as

well as material changes in metal prices subsequent to the date of an estimate, may justify a revision of such estimates.