Mining Intelligence and News

La Guitarra Mine

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Mine TypeUnderground
StatusCare and Maintenance
  • Silver
  • Gold
Mining Method
  • Overhand Cut & Fill
  • Longhole stoping
Backfill type ... Lock
Production Start... Lock
SnapshotThe La Guitarra Mine is a high-grade underground mine that was operated up to August 2018, currently is on care and maintenance and available for a prompt restart.

On February 8, 2024, Sierra Madre Gold and Silver Ltd. retained TechSer Mining Consultants Ltd., of Vancouver, B.C., to complete the Mine Restart Study ("MRS"). This work will include an estimation of underground mine material for the Guitarra, Coloso and Nazareno mines and the Los Angeles bulk tonnage deposit. Additional evaluations will include an operating cost estimate covering the mine and recovery plant. The MRS is expected to be completed in Q2 2024.

The MRS will study an initial production level of 350 tonnes per day. Additional evaluation will be completed on potentially increasing the grinding circuit's capacity to greater than 500 tonnes per day.

All circuits in the processing plant are undergoing maintenance and rehabilitation work which would be required for the resumption of operations.


Sierra Madre Gold and Silver Ltd. 100 % Indirect
On March 30, 2023, First Majestic Silver Corp. closed its previously announced transaction to sell its 100% owned past producing La Guitarra Silver Mine to Sierra Madre Gold & Silver Ltd.

Deposit type

  • Vein / narrow vein
  • Epithermal


Vein deposits at La Guitarra have physiochemical and mineralogical characteristics of the Intermediate Sulphidation epithermal type and fit thevein deposit model proposed by Buchanan(1981). Epithermal deposits form atshallow depths in volcanic-hydrothermal and geothermal environments. They define a spectrum with two end members, low and high sulfidation (Hedenquist et al., 1998). Intermediate Sulphidation epithermal deposits form part of the epithermal spectrum and their genesis is complex due to the involvement of fluids with meteoric or magmatic origin during their formation and to the fluid evolution.

There are in excess of one hundred epithermal veins within the property in five main vein systems: Comales–Nazareno, Coloso (Jessica and Joya Larga veins), La Guitarra (NW, Central and SE zones), Mina de Agua and El Rincón. The vein systems at La Guitarra property form a belt with an approximate width of 4 km that strikes NW – SE in excess of 15 km. Individual veins pinch and swell and vary in width from tens of centimetres to more than twenty metres. Economic zones, widths usually between 1 and 4 metres, are embedded in quartz (vein structure) having widths up to 20 metres (e.g. Guitarra vein). The ore shoots or economic zones can either be localized in the hanging wall or the foot wall of the vein structure.

Gangue mineralogy consists of banded quartz, amethyst quartz, colloform chalcedony, finegrained crystalline quartz, calcite, fluorite, pyrite, marcasite, barite, anhydrite, illite–smectite, adularia and alunite. Anhydrite and alunite veins are observed mostly filling narrow fractures. The ore mineralogy consists of proustite – pyrargyrite solid solution, electrum, acanthite, polybasite, sphalerite, galena and chalcopyrite. Secondary minerals such as malachite and smithsonite – hydrozincite (calamines) have been observed in some of the veins at Mina de Agua. According to Camprubí et al. (2006), the vein stratigraphy of the La Guitarra deposit can be grouped in three mineralization stages: a) stage I is dominated by a base-metal sulfide association whereas stages II and III contain most of the precious-metal assemblages. Relative mineral abundance in each mineralization stage shows an increase on the content of Ag–Au bearing phases with time (Camprubí et al., 2006). Stage II is the most important in volume and contains the main mineralization. Base-metal sulfides precipitated early in all mineralization stages, their relative content increases with depth at any stage (Camprubí et al., 2006).

The main textures observed in the veins are coarse banding, fine banding, colloform, bladed quartz, and breccia textures. Fine banding, colloform banding (particularly dark bands containing fine grain sulfides) and bladed quartz textures have been observed to correlate with higher silver and gold concentrations. This association is not surprising since colloform banding (chalcedony) and bladed textures are commonly associated with boiling and boiling is an important mechanism for deposition of precious metals in the epithermal environment. The breccias usually contain angular quartz clasts that range in size from a few millimetres to tens of centimetres and are supported by a silicified matrix or cemented by quartz or quartz and marcasite.

Spatial association, orientation, mineralogy as well as gas chemistry and microthermometry analysis suggest that the veins along the property may have had a common source and therefore could be cogenetic. Thus, the aforementioned characteristic could apply to the five vein systems.



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Mining Methods


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Crushers and Mills


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Silver Metal in concentrate oz 358,919611,705923,597945,662
Gold Metal in concentrate oz 3,5645,5538,1816,907
Silver Equivalent Metal in concentrate oz 641,1791,019,1111,523,6881,457,728

Operational metrics

Daily milling capacity  ....  Subscribe  ....  Subscribe  ....  Subscribe500 t500 t500 t500 t
Daily milling rate  ....  Subscribe  ....  Subscribe  ....  Subscribe385 t365 t
Tonnes milled  ....  Subscribe  ....  Subscribe  ....  Subscribe80,435 t127,842 t155,696 t174,003 t

Production Costs

Credits (by-product) Silver USD -11.06 / oz  
Cash costs Silver USD 19.9 / oz  
Total cash costs Silver USD 22.4 / oz   22.6 / oz  
Total cash costs Silver USD 9.79 / oz **   11.5 / oz **  
All-in sustaining costs (AISC) Silver USD 16.1 / oz **   19 / oz **  
** Net of By-Product.

Operating Costs

UG mining costs ($/t milled) USD 34.7  34.8  
Processing costs ($/t milled) USD  ....  Subscribe  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe  ....  Subscribe  ....  Subscribe


Sustaining costs M USD 2.1   4.2  
Capital expenditures M USD 5.3   9.8  
Revenue M USD 9.3   15.4  
Operating Income M USD -3.3   -3.3  

Heavy Mobile Equipment


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Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Sep 6, 2023
....................... Subscription required ....................... Subscription required Subscription required May 23, 2024

...... Subscription required ...... Subscription required 2015

Aerial view:


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