Geology

GKZ, KAZRC/JORC and GB/T 17766-2020 reserve classifications in Kazakhstan: how the categories compare

GKZ categories (A–C2, P1–P3), KAZRC/JORC and GB/T 17766-2020: approximate correspondence, historical estimates and why Soviet C1 and C2 are not JORC.

Updated 26 September 2026 · 14 min read

Contents

There is no direct conversion between the Soviet State Reserves Committee (GKZ) categories (A, B, C1, C2), the KAZRC/JORC codes and China's GB/T 17766-2020 standard. In the 2019 comparison by the Committee of Geology of the Republic of Kazakhstan, A, B and part of C1 reserves are closest to Measured resources (探明资源量), C2 and the rest of C1 to Indicated (控制资源量), and P1 prognostic resources are placed alongside Inferred (推断资源量). But under JORC a resource cannot be estimated without sampling data, so we do not call P1 a resource: it is a forecast. P2 and P3 relate to deposits not yet discovered and have no direct equivalents. GKZ reserves are estimated in situ, without losses or dilution, so they are closer to resources than to JORC Ore Reserves. A figure can be labelled "KAZRC" or "JORC" only after it has been re-estimated by a Competent Person using data that meets the code's requirements; until then, the Soviet figure is a historical estimate.

The three systems and what they are for

	GKZ (USSR, Kazakhstan)	KAZRC, JORC (CRIRSCO family)	GB/T 17766-2020 (PRC)
Issued by	USSR Council of Ministers (1981); in Kazakhstan, the Ministry of Industry and Construction (2026 Instruction)	KAZRC Association; JORC Committee; template: CRIRSCO	State Administration for Market Regulation and Standardization Administration of the PRC; proposed by the Ministry of Natural Resources of the PRC (自然资源部)
Purpose	State records and the state reserves balance	Public reporting to investors	State statistics, subsoil management, disclosure of information
Who is responsible for the figure	State expert review	A named Competent Person	The standard has no Competent Person

GKZ: A, B, C1 and C2 reserves and P1–P3 prognostic resources

The Soviet classification was approved by Resolution No. 1128 of the USSR Council of Ministers of 30 November 1981. By degree of study, reserves are divided into explored (A, B, C1) and preliminarily estimated (C2), and prognostic resources into categories P1, P2 and P3 (para. 8). By economic significance, reserves are divided into balance and off-balance reserves (para. 16). They are estimated "as present in the subsoil, without accounting for losses and dilution in mining, beneficiation and processing" (para. 4).

Kazakhstan has kept this logic. The current Instruction on the Classification of Reserves (Order No. 208 of the Minister of Industry and Construction of the Republic of Kazakhstan of 28 April 2026) provides for:

C2 as preliminarily estimated reserves, and C1, B and A as confirmed (commercial) reserves (para. 15);
P1 as resources of new targets identified by prospecting or of the flanks of known deposits (para. 25), P2 as resources of presumed new deposits (para. 24), and P3 as resources of expected deposits estimated by analogy (para. 23);
balance (active and inactive) and off-balance reserves (para. 28); reserves that have passed state expert review are entered on the state reserves balance (para. 31);
estimation without adjustments for losses and dilution (para. 7).

P1–P3 are a forecast, not reserves.

KAZRC and JORC: resources and reserves under the CRIRSCO template

The 2012 JORC Code is in force: a review is under way, but as of August 2026 no new edition has been introduced. The KAZRC Code is in force in its December 2022 edition, based on the 2019 CRIRSCO template. The definitions used by CRIRSCO members match the template in substance. The levels are:

Exploration Results: sampling, drilling and geophysical data. No tonnage or average grade is attributed to them (JORC Clause 18; KAZRC Arts. 19–20).
Exploration Target: potential expressed only as a range of tonnage and grade, with a statement that the estimate is conceptual (JORC Clause 17; KAZRC Art. 17). Under JORC it is not put in a headline and is accompanied by a Competent Person statement.
Mineral Resources: a concentration with "reasonable prospects for eventual economic extraction"; a resource is not estimated without sampling data (JORC Clause 20). Categories: Inferred, Indicated and Measured (JORC Clauses 21–23; KAZRC Arts. 23–25). Inferred resources are not converted to reserves (Clause 21).
Ore Reserves (Mineral Reserves in KAZRC): the economically mineable part of Measured and Indicated resources, including dilution and losses, supported by a pre-feasibility or feasibility study with Modifying Factors applied (JORC Clause 29; KAZRC Art. 31). Categories: Probable and Proved (JORC Clauses 30–31; KAZRC Arts. 32–33).

The category is assigned by the Competent Person (JORC Clauses 24 and 32): a member of the AusIMM, the AIG or a recognised professional organisation with enforceable disciplinary powers, with at least five years' experience on the same type of deposit (JORC Clause 11; KAZRC Art. 11).

GB/T 17766-2020: 资源量 and 储量

The standard 固体矿产资源储量分类 (Classification of Solid Mineral Resources and Reserves) was published on 31 March 2020, took effect on 1 May 2020 and replaced GB/T 17766-1999. It reduced the 16 types of resources and reserves to five, and the exploration stages to three: 普查, 详查 and 勘探 (foreword).

资源量 (resources, cl. 2.7) are divided by level of geological confidence into 推断资源量 (inferred, cl. 2.8), 控制资源量 (indicated, cl. 2.9) and 探明资源量 (measured, cl. 2.10). The English equivalents are given in the standard itself.
储量 (reserves, cl. 2.12) are the economically mineable part of 探明资源量 and 控制资源量, taking ore losses and dilution into account. They are divided into 可信储量 (probable, cl. 2.13) and 证实储量 (proved, cl. 2.14). Converting resources into 储量 requires at least a pre-feasibility study (预可行性研究) or an equivalent assessment (cl. 4.3).
Only these five terms may be used in publications (cl. 5.1), and 资源量 and 储量 are not added together (cl. 5.2). Potential mineral resources (潜在矿产资源) are not expressed as 资源量 (Annex A, cl. A.3).
Older reports use the 1999 codes: under Notice No. 1370 of 2020 of the Ministry of Natural Resources of the PRC, code 333 is converted to 推断资源量 and 334? to 潜在矿产资源.

At the end of 2025 the China Association of Mineral Resources Appraisers (CAMRA) completed its accession to CRIRSCO. GB/T 17766-2020 nevertheless remains a national standard, and it has no concept of a Competent Person.

Summary table: approximate correspondence

The table is a guide for negotiations, not a conversion rule. There is no direct conversion: the KAZRC or JORC category is assigned by a Competent Person after checking the data. The GKZ column follows the comparison by the Committee of Geology and Subsoil Use of the Republic of Kazakhstan (UNECE, 2019); in the Exploration Results and Exploration Target rows it is our own explanation. The Chinese terms are matched using the English equivalents given in GB/T 17766-2020 itself.

KAZRC / JORC / CRIRSCO	GB/T 17766-2020	GKZ (USSR, Kazakhstan)	Caveat
Exploration Results	No separate category	Prospecting results without an estimate	No tonnage or average grade
Exploration Target	None; 潜在矿产资源 are not expressed as 资源量	P1–P3, if the Competent Person considers the basis sufficient	Only as a range and with a caveat (JORC Clause 17)
Inferred	推断资源量	P1, only in the comparison by the Committee of Geology of Kazakhstan	No sampling data, no resource (JORC Clause 20); P1 remains a forecast
Indicated	控制资源量	C2 and part of C1	The boundary is drawn by the Competent Person
Measured	探明资源量	A, B and part of C1	Where data quality is confirmed
Probable Ore Reserve	可信储量	Mineable reserves of evaluated deposits (with losses and dilution)	A pre-feasibility or feasibility study is required
Proved Ore Reserve	证实储量	Mineable reserves of explored deposits	Only from Measured

Why Soviet C1 and C2 cannot be called JORC

There is no Competent Person. A JORC report is based on documentation prepared by a Competent Person and is issued with their written consent (Clause 9), and it is the Competent Person who chooses the category (Clause 24). Soviet reserves were approved by a state commission under the rules of their time.
Nothing may be published outside the code's categories (JORC Clause 26; KAZRC Art. 28; CRIRSCO template 2024, paras 7.18 and 8.20). "C1" is not a JORC category.
"Reserves" means different things. GKZ reserves are estimated in situ without losses and dilution, whereas Ore Reserves include them and require a pre-feasibility or feasibility study (JORC Clause 29). The words "ore" and "reserves" are not applied to resources (Clause 28). Even A+B+C1 do not become Proved or Probable without design work.
The economics of past decades. Balance reserves were defined using the cut-off parameters (konditsii) of their time, while the Competent Person has to establish reasonable prospects for extraction afresh (JORC Clause 20). Off-balance reserves do not automatically become resources.
Data verification. JORC Table 1 requires disclosure of sampling methods, assay quality control (standards, blanks, duplicates) and verification of intersections, including by twinned holes. If the primary data have not survived, the category may turn out lower than the Soviet one.

Individual high-grade samples must not be presented out of context (JORC Clause 19), and top-cutting of high-grade assays must be disclosed explicitly (JORC Clause 20; KAZRC Art. 22). A high-grade outlier (spike) is not an average grade.

Historical estimates: what they are and how to refer to them

In JORC practice these terms are defined by the ASX Listing Rules, to which the JORC website refers. A historical estimate is an estimate of quantity and grade based on data prepared before the JORC Code was introduced, which the company has not confirmed as Mineral Resources or Ore Reserves under JORC. A foreign estimate is an estimate made under the standard of another jurisdiction before the company acquired an interest in the area, and likewise not confirmed under JORC (Chapter 19).

ASX Listing Rule 5.12 requires a company to:

state the source and date of the estimate and explain how its categories differ from JORC (5.12.1–5.12.2);
describe the reliability of the estimate and the work needed to bring it into line with JORC, with its timing and funding (5.12.4, 5.12.7, 5.12.8);
state, in proximity and with equal prominence, that the estimate is not reported under JORC; that a Competent Person has not done sufficient work to classify it; and that it is uncertain whether it can be classified after verification (5.12.9);
include a statement by a named Competent Person (5.12.10).

Such estimates are not included in economic analysis (a scoping study, pre-feasibility or feasibility study; 5.11). The only exception is for estimates under SAMREC, NI 43-101 and PERC that are acceptable to the ASX; Soviet estimates are not on that list.

The KAZRC Code has no separate article on historical estimates: Table 1 (section 1.4, "History") requires known historical estimates to be described, and public reporting of resources outside the code's categories is not permitted (Art. 28). The 2024 CRIRSCO template works the same way.

A correct wording reads: "The C1+C2 gold reserves estimated by the USSR GKZ are a historical estimate. This is not a JORC or KAZRC estimate; a Competent Person has not carried out work to classify it, and it is not known whether it will be confirmed."

Status of KAZRC in Kazakhstan

The KAZRC Code was first published in June 2016. The KAZRC Association has been a member of CRIRSCO since 2016; according to the association, the code has been enshrined in legislation since 2018.
Under the current Code of the Republic of Kazakhstan "On Subsoil and Subsoil Use" (the Subsoil Code), an application for a solid minerals mining licence must be accompanied by a report on the estimation of resources and reserves (Art. 204(3)(6)) prepared by a Competent Person under the KAZRC Code (Art. 204(7)).
A Competent Person is a member of a professional organisation under the KAZRC Code or of a foreign organisation recognised by it (Art. 194(8)).
Data from a KAZRC report are included in state records; the authority reviews the report within 30 calendar days (Art. 72(9)). If resources, taking production and losses into account, turn out to be more than 25% lower than the previously approved reserves of commercial categories, the authority hears the subsoil user and the Competent Persons (Art. 72(9)(4)).
A transitional provision preserves the former route, reserves estimation under Art. 121 of the repealed 2010 Law (state subsoil expert review), for contracts and mining licences issued before 31 December 2023 and for applicants for a mining licence (Art. 278(10)). For uranium, either a Competent Person's report under KAZRC or a reserves estimation report is submitted (Art. 180(2)).

The bottom line: in 2026, KAZRC and the national A–C2 and P1–P3 classification operate in parallel in Kazakhstan. How a foreign investor can acquire a subsoil use right as such is covered in our guide for foreign investors, and the exploration licence in a separate guide.

How QAZNEDR HOLDING states the standard in teasers

On the site and in the cards on the areas page, we write:

reserves follow USSR GKZ categories (A, B, C1, C2) or are marked as a historical estimate;
P1–P3 are a forecast, not reserves;
every figure is labelled by type: average, maximum sample or forecast.

None of the areas on display has yet been estimated under KAZRC or JORC. We label the average grade separately from high-grade outliers (spikes) and heavy-mineral (schlich) samples. The areas on display are free according to our check as of the date shown on the card; they do not belong to the holding, and subsoil use rights are granted by the state. The name, coordinates and materials are shared at a meeting after an NDA is signed.

How QAZNEDR HOLDING can help

Our geologists review the archival geological reports on an area: which categories, what supports them, and where the gaps are in sampling, quality control and metallurgical testwork.
We label every figure: GKZ, historical estimate or forecast; average or high-grade outlier (spike).
We prepare an area for estimation by a Competent Person under KAZRC or JORC: we assemble the data for Table 1 and draw up a programme of verification work.
We carry out due diligence before a deal: we reconcile the figures with the primary documentation and state records, and handle the legal side together with lawyers.
We provide support but do not guarantee the outcome: the category is assigned by a Competent Person, and the licence is granted by the state. The areas are on the areas page; for questions, use the contact page.