Trading of mineral products (not by holders of mining rights) is reserved to companies majority-owned by Mozambican citizens.
"Article 2
(Scope of application)
1. This Law establishes the general principles that govern the exercise of the rights and obligations regarding the use and re-use of mineral resources, including mineral water. 
2. The exercise of rights and obligations regarding the use and re-use of oil, natural gas, associated methane gas and associated natural gas is excluded from the scope of this Law. 
[...]
Article 8
(Mining contract)
1. The Government may enter into a mining contract with the holder of a Prospecting and Research Licence and Mining Concession, in terms to be regulated.
2. The mining contract, among other clauses, should contain the following: a) State participation in the mining venture; b) Minimum local content;
[...]
Article 22 
(Acquisition of goods and services)
1. The acquisition by the mining holders of goods or services above a certain value, in terms to be regulated, shall be made by public tender and this shall be published in the most relevant newspapers.
2. Single or collective foreign legal persons providing services to mining operations shall be associated to Mozambican single or collective legal persons in accordance with the regulation.
3. In the evaluation of the public tender proceedings the following selection criteria must be considered: quality of the product, price, delivery time and guarantees offered.
4. The mining holder must give preference to local products and services.
[...]
CHAPTER V-  Small scale and artisanal mining
Section I - Mining certificate
Article 45
(Conditions and validity period)
1. The mining certificate is assigned to national single or collective legal person with judicial capacity that proves having technical and financial capacity to carry out small-scale mining operations. 
[...]
CHAPTER VI- PERMITS
Section I - Mineral Resources for building materials
Article 53
(Traditional uses of mineral resources for building materials)
The extraction of natural resources for building materials does not require a mining permit or authorization when the following requirements are met: a) carried out by national citizen in the extent and way allowed by the local customs and in the land where it is common to carry out such extraction; b) housing, warehousing and other facilities' construction; c) handcrafted ceramics production by users of the land.
[...]
Section III - Commercialization of mining products
Article 59
(Requirements)
1. The purchase and sale of mineral products not carried out under a mining concession, mining certificate or mining pass shall be made by a national, single or collective, legal persons constituted by national citizens and registered in accordance with the laws in force in the Republic of Mozambique in the terms of specific regulation.
2. The commercialization of mineral products extracted under a mining concession, mining certificate and mining pass does not require a trading authorization and it is subject to the legislation in force in the Republic of Mozambique.[...]" (Mining Act No. 20/2014 [unofficial translation)
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"Annex 1 - Glossary [...]
(pp) National legal person: person incorporated and registered in Mozambique with management, headquarters and effective management in national territory, and whose capital is majority Mozambican.[...]"(Decree No. 31/2015 approving the Mining Act Regulation [google translation])
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"Article 2 [...]
3. 1. The commercialization of raw diamonds, precious metals and gemstones, through the commercialization license, is only allowed to national individuals or legal entities, in accordance with the Mining Law.[...]" (Decree No 63/2021 approving the Regulations on raw diamonds, precious metals and gemstones trading [google translation])
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[not reproduced here] (Decree No. 25/2015 Approves the Regulation for the Marketing of Diamonds, Precious Metals and Gems, Art. 6)
Mining Act No. 20/2014
Decree No. 31/2015 approving the Mining Act Regulation
Decree No 63/2021 approving the Regulations on raw diamonds, precious metals and gemstones trading
Decree No. 25/2015 Approves the Regulation for the Marketing of Diamonds, Precious Metals and Gems
[<a href="https://113dstor001.s3-eu-west-1.amazonaws.com/Community+Development+in+Mining/Mozambique/Mozambique_Mining_Law_Law_No._20_2014_English.pdf">Act</a>],[<a href="https://inami.gov.mz/index.php/files/97/Legislacao%20Mineira/56/Regulamento%20da%20Lei%20de%20Minas.pdf">Decree</a>],[<a href="https://inami.gov.mz/images/Contratos/Decreto-n--63_2021_64_2021-regulamento-de-comercializacao-de-recursos-mineiras.pdf">Decree</a>],[<a href="https://archive.gazettes.africa/archive/mz/2015/mz-government-gazette-series-i-dated-2015-11-20-no-93.pdf">Decree</a>]