Exploration Program & Resources Estimate
Prior to exercising the option agreement in 2005, Great Panther conducted a 30-hole (7,437-metre) diamond drilling program that tested five separate areas on the property. Three of these areas, Las Trancas, Don Benito and Hormiguera represent portions of the same vein that extends for more than four kilometres across the property. The two other areas represent parallel vein systems approximately one kilometre to the northwest (Argentina) and two kilometres to the southeast (El Rosario). Several other veins are known on the property.
Since 2005, continued drilling has been conducted to extend the mining potential of known veins and explore other veins. The acquisition of the 94-hectare La Prieta concession in the Topia District in late 2009 was a strategic move that lead to additional production. La Prieta is within easy trucking distance of the Topia plant.
Since acquiring the Topia Mine property, sampling of the workings, and surface and underground drill programs have been ongoing. The latest Mineral Resource Estimate was classified according to the CIM Definition Standards on Mineral Resources and Mineral Reserves and, as such, is consistent with the requirements of NI 43-101. It has an effective date of November 30, 2014 and replaces the previous estimate completed by Great Panther Silver Limited (Brown, R.F. and Sprigg, L.) in 2013. Reporting delays were caused by challenges relating to the complexity of the multiple vein zones at Topia.
The November 2014 Measured & Indicated ("M&I") Mineral Resource Estimate totals 346,200 tonnes garading 624g/t silver, 1.31g/t gold, 4.50% lead and 4.19% zinc (11.58 million silver equivalent ounces (“Ag eq oz”)). In addition, the Inferred Mineral Resource Estimate totals 357,400 tonnes grading 592g/t silver, 1.31g/t gold, 3.44% lead and 3.96% zinc (11.05 million Ag eq oz). (See Table 1 for breakdown)
The November 2014 Mineral Resource Estimate provides an update for 40 veins from nine mining areas. It is based on an approximate average Net Smelter Return ("NSR") cut-off value of US$180/tonne, corresponding to 2014 mining, processing, concentrate shipment and treatment, and general and administrative costs for each mining area. Capping of grades and a minimum true width of 0.30 metres were individually applied to each of the veins making up the summary in Table 1 bellow.
While most of the current resource base came from Great Panther's diamond drilling and underground development, the resource estimated for certain veins on the property (e.g. Argentina) came largely from the verification of Peñoles' sampling on levels that are planned for access in 2015 and later, and are still intact. The majority of Great Panther's mining to date has come from new mine development on veins reported in these estimates. The new total contained metal for the mineral resource categories is shown in Table 2 below.
Due to the steep topography and the nature of the narrow veins at Topia, surface drilling is typically widely spaced and is used as a guide for underground development by locating and confirming structural continuity and grade, while development by drifting, sampling, and some underground drilling along the veins defines the M&I mineral resource. Accordingly, surface drilling is used to determine Inferred resources.
Table 1: Mineral Resource Estimate
| Topia Mine Mineral Resource Estimate, effective date November 30, 2014 |
| Category || Tonnage || Ag g/t || Au g/t || Pb % || Zn % |
| Total Measured || 180,400 || 606 || 1.44 || 4.26 || 4.52 |
| Total Indicated || 165,800 || 644 || 1.17 || 4.75 || 3.82 |
| Total Measured & Indicated || 346,200 || 624 || 1.31 || 4.50 || 4.19 |
| Total Inferred || 357,400 || 592 || 1.31 || 3.44 || 3.96 |
- CIM Definitions were followed for Mineral Resources.
- Mineral Resources are reported using different Net Smelter Return (NSR) cut-off values for the different mines as follows: US$167/t for the 1522 Mine, US$197/t for Argentina, US$153/t for Durangueno, US$189/t for Hormiguera, US$196/t for Recompensa, US$173/t for El Rosario, and US$204/t for La Prieta.
- Area-specific bulk densities are as follows: Argentina - 3.06t/m3; 1522 - 3.26t/m3; Durangueno - 3.12t/m3; El Rosario - 3.00t/m3; Hormiguera - 2.56t/m3; La Prieta - 2.85t/m3; Recompensa - 3.30t/m3.
- A minimum mining width of 0.30 metres was used.
- Mineral Resources are estimated using metal prices of: US$1,200/oz Au, US$17.00/oz Ag, US$0.90/lb Pb, and US$0.95/lb Zn. Silver equivalent calculations used the same metal pricing.
- Totals may not agree due to rounding.
Table 2: Contained metal (all veins)
| Category || Tonnage || Ag oz || Au oz || Pb lbs || Zn lbs || Ag eq oz |
| M & I Resource || 346,200 || 6,950,000 || 14,560 || 34,320,000 || 31,950,000 || 11,580,000 |
| Inferred Resource || 357,400 || 6,810,000 || 15,060 || 27,140,000 || 31,240,000 || 11,050,000|
The Company plans to continue the systematic replacement of annual production with new resources. This "rolling resource" is typical for underground mines as it is often not cost-effective to define a large resource/reserve in advance of mining.
Mineralization within the Topia Mine is that of a typical silver-lead-zinc epithermal vein system, formed along a series of northeast trending faults within the Tertiary-aged Lower Series Volcanics. The mined vein horizon consists of quartz, galena, sphalerite and pyrite and lesser amounts of arsenopyrite, marcasite, chalcopyrite, silver-rich sulphosalts, electrum, muscovite and carbonates.
At Topia, the historically mined ore-grade or "productive" veins are confined to a limited vertical extent of 200 to 300 metres, but can extend laterally along strike for as much as 4 kilometres. This productive vein horizon grades downward into barren coarse-grained quartz, and upwards into barren, cherty, quartz-calcite-barite. Historically, the three most prolific veins on the property were the Veta Madre, Argentina and Cantarranas. The Topia District contains multiple veins, most of which lie on the Great Panther property.
The Topia Mining District is one of the oldest in Mexico, with the discovery of silver dating back to 1538. Artisanal mining continued for centuries until the Topia Silver Mine was opened in 1952 by Peñoles (now Fresnillo), Mexico's largest silver producer. Peñoles consolidated the claim ownership, built a road into the area, and constructed a 200 tonne per day mill on site. They operated the mine continuously until 1989, when they sold it to a former mine manager, who continued production on a small scale until 1999.
Total historical production for the district has been estimated at 30 million ounces of silver. The recorded production for 1952-1999 exceeds 15 million ounces of silver, as well as 18,500 ounces of gold, 48,000 tonnes of lead and 44,500 tonnes of zinc. The on-site mill complex treated the ore and produced lead and zinc concentrates that were shipped to the Peñoles smelter in Torreon. Records for Peñoles' 38 years of production indicate average mill head grades of 437 g/t silver, 0.87 g/t gold, 3.9% lead and 4.2% zinc. Overall average metal recoveries were silver-86%, gold-55%, lead-94% and zinc-85%.