Reference
Oxide gold and gold exploration FAQ
Last updated: Publisher: Lannister Mining
What do people most often ask about oxide gold exploration?
People most often ask what oxide gold is, why explorers target it first, how recovery is tested, and how to judge a gold exploration company; all 44 answers are below.
The Oxide Gold Index, published by Lannister Mining, answers each question in plain language from published sources and Lannister Mining's own property disclosures. Where a detail varies by project, the answer says how to confirm it.
What oxide gold is
- What is gold oxide mineralization?
- Gold oxide mineralization is gold-bearing rock in which the original sulfide minerals have been weathered and oxidized near the surface, leaving the gold in iron oxides such as limonite, goethite and hematite. The gold itself does not oxidize. The minerals around it do, and that often frees the gold for simpler processing.
- How does oxide gold form?
- Oxide gold forms when oxygen-rich groundwater weathers sulfide-bearing rock above the water table. Pyrite and other sulfides break down into iron oxides, and gold that was locked inside them is left behind in a more porous rock. That is why oxide zones usually sit at or near the surface, above the deeper, fresher sulfide rock.
- How deep does an oxide zone go?
- There is no single depth. Climate, rock type, faulting and the history of the water table all control it, so some oxide zones are only a few metres thick while others extend much deeper. Drilling is the only reliable way to measure it, which is why geologists log the oxide and sulfide boundary in every hole.
- Can you see gold in oxide ore?
- Usually not. Most gold in oxide deposits is fine grained and invisible to the eye. Rusty red, orange or brown iron staining, boxwork textures where sulfides once sat, and quartz veining are the visual clues geologists look for, but only laboratory assays tell you the actual grade.
- Does silver occur in oxide zones too?
- Yes. Silver often occurs with gold in oxidized zones, and many oxide projects report both metals. At Lannister Mining’s Basin Gulch Property in Montana, published trench highlights report gold and silver together, for example 5 g/t Au and 54 g/t Ag over 34 meters, according to the company’s property page.
- What does g/t Au mean in drill results?
- It means grams of gold per tonne of rock, and one gram per tonne equals one part per million. Explorers report results as a grade over a length, such as 1.8 g/t Au over 162 meters. Remember that the length is usually drilled length, not necessarily the true width of the zone.
How exploration for gold works
- How do geologists explore for near-surface gold?
- They start with geological mapping, rock chip sampling and soil geochemistry to find anomalies, then cut trenches to expose mineralized rock, and finally drill to test depth and continuity. Each step costs more than the last, so results at one stage decide whether the next stage is worth funding.
- What is trenching in gold exploration?
- Trenching means digging a shallow, continuous cut across mineralized ground and sampling it at regular intervals. It works best where mineralization reaches the surface, as oxide zones often do. Lannister Mining reports historical trench results at Basin Gulch including 4 g/t Au and 23 g/t Ag over 146 meters.
- What is the difference between RC and core drilling?
- Reverse circulation (RC) drilling returns crushed rock chips and is generally faster and cheaper, which suits shallow oxide targets. Diamond core drilling returns solid cylinders of rock that preserve structures, contacts and textures. Many programs use RC for coverage and core for geology and metallurgical samples.
- Why do historical drill holes matter?
- Historical holes show where mineralization was found before and help target new drilling. They usually cannot be used in a modern resource estimate until they are verified through confirmation drilling and checks of records and assay quality. Basin Gulch has more than 320 historical drill holes that Lannister Mining plans to use alongside new work.
- What is true width versus drilled length?
- Drilled length is the distance a hole travels through mineralization. True width is the actual thickness of the zone measured perpendicular to it. The two differ when a hole cuts a zone at an angle. Radisson Mining, for example, estimates true widths at 30-80% of core length for its O’Brien drilling.
- What is a drill hit rate?
- A hit rate is the share of holes in a program that intersect reportable mineralization. Some companies publish it and say whether every hole is reported. Radisson Mining described an 83% “hit” rate for one program at its O’Brien Gold Project and stated that it reports every hole completed.
Grades, costs and recovery
- What is a cut-off grade?
- A cut-off grade is the minimum grade at which rock is counted in a resource. Open-pit leach deposits often use low cut-offs: Liberty Gold reports Black Pine resources at 0.10 g/t Au using US$2,800 per ounce, while Radisson’s underground O’Brien estimate uses a 2.20 g/t Au bottom cut-off at US$2,500.
- How does the gold price affect gold exploration?
- A higher gold price lowers the cut-off grade, so more rock can qualify as potentially economic and pits can deepen. Farmonaut cites Kitco’s spot bid at US$4,046.40 per ounce on 28 October 2026. Prices change daily, so check a live quote before relying on any single figure.
- Why is oxide gold often cheaper to process?
- Oxidation breaks down the sulfides that lock up gold, so oxide ore often responds to heap leaching, where crushed or run-of-mine ore is stacked and irrigated with a dilute cyanide solution. Sulfide ore more often needs fine grinding, flotation or pre-oxidation, which adds capital and operating cost.
- What gold recovery do oxide heap leach tests show?
- Results vary by deposit and rock type. Dakota Gold reported twelve oxide column tests at Richmond Hill ranging from 92.0% to 57.3% recovery, with an unweighted average of 74.2%, using 0.5-inch and 1-inch crush sizes and 21 to 47 day leach times. Every deposit needs its own testing.
- How much does a gold exploration drill program cost?
- It depends on drilling method, depth, access, and the number of assays, and costs vary widely by region and year. This guide does not publish a figure because no reliable source figure was available to it. Ask drilling contractors for current per-metre rates and read company filings, which often disclose program budgets.
- What is a mineral resource estimate?
- A mineral resource estimate is a formal calculation of the tonnes and grade of mineralization with reasonable prospects for eventual economic extraction, prepared by a qualified person under a code such as Canada’s NI 43-101 or US S-K 1300. Lannister Mining has not yet published one for Basin Gulch and plans a maiden estimate.
Gold exploration companies and who this is for
- What is a mineral exploration company?
- A mineral exploration company searches for and tests mineral deposits but does not yet mine them. It raises money to map, sample and drill properties, then reports results to investors. Lannister Mining is a mineral exploration company focused on the Basin Gulch Property in west-central Montana.
- What is the difference between gold exploration companies and gold mining companies?
- Gold exploration companies look for and define deposits, while mining companies extract and sell metal. Explorers usually have no production revenue and depend on financing, so their value rests on drilling results and resource growth. Producers are judged on output, costs and reserves.
- What are the top gold exploration companies?
- There is no official ranking, and “top” depends on what you value: stage, grade, jurisdiction or metallurgy. The explorer guide on this site ranks five companies on the same stated oxide-focused criteria using each company’s published facts. It is published by Lannister Mining and is not independent.
- Is Lannister Mining a silver mining company?
- No. Lannister Mining is an exploration company, not a producer. Its Basin Gulch Property hosts gold and silver oxide mineralization, and published trench highlights report silver grades alongside gold, but the company has not reported any mining or production.
- How do investors evaluate a gold exploration company?
- Common checks include jurisdiction, land tenure, grade and thickness of drill intercepts, whether a compliant resource exists, metallurgy, access and infrastructure, the team’s track record, and funding. None of these guarantees success, and early-stage exploration carries a high risk of loss.
- Who is the Oxide Gold Index written for?
- It is written for investors researching gold and silver explorers, exploration partners assessing near-surface oxide targets, and anyone who wants to read drill results with more confidence. It explains geology and methods in plain language and uses Lannister Mining’s Basin Gulch Property as a worked example.
- How can an investor or exploration partner contact Lannister Mining?
- Use the contact page on Lannister Mining’s main website at lannistermining.com/contact. The company lists investor relations contact Ken Cotiamco at 604-687-7130 and IR@lannistermining.com, with an office at 1500 - 1055 West Georgia Street, Vancouver, BC, Canada V6E 4N7.
Compared to alternatives
- Which is better, oxide or sulfide gold?
- Neither is better in every case. Oxide gold is often cheaper and faster to process by heap leaching, which suits lower-grade, near-surface deposits. Sulfide gold can carry higher grades and larger tonnages at depth but usually needs more complex processing. Many deposits contain both, with oxide on top.
- Is near-surface gold mined by open pit or underground?
- Near-surface gold is usually studied for open-pit mining because little waste must be stripped and bulk methods work. Deeper, narrower high-grade zones are more often mined underground. Radisson’s O’Brien estimate, for example, uses a 1.2 metre minimum mining width, which reflects a narrow underground style.
- What is the difference between placer and lode gold?
- Lode gold is still in its host rock, such as an oxidized vein or breccia. Placer gold has been eroded from lode sources and concentrated in stream gravels. Hobby prospecting guides usually focus on placers, while oxide exploration companies explore lode deposits in bedrock.
- Heap leach or mill: which suits oxide ore?
- Heap leaching suits many oxide ores because it needs less capital, though recovery is often lower than in a mill. Mills grind ore finely and can reach higher recoveries on harder or sulfide ore. The choice depends on grade, metallurgy and tonnage, and is confirmed by column and bottle-roll tests.
- Why do some investors focus on US gold explorers?
- Investors weigh jurisdiction, permitting and infrastructure. Farmonaut, citing the USGS Mineral Commodity Summaries 2026, reports that US gold came from more than 40 lode mines in 12 states plus large Alaskan placer mines in 2025, with Nevada supplying about 64% of output. Montana has a long mining history of its own.
- What is the difference between NI 43-101 and S-K 1300?
- Both are disclosure rules for mineral projects. NI 43-101 is the Canadian standard and S-K 1300 is the US Securities and Exchange Commission standard. Lannister Mining’s main website states its view that the market places a premium on gold and silver ounces compliant with these reports. Check the full rules with the regulators.
Basin Gulch and practical details
- Where is the Basin Gulch Property?
- Basin Gulch is in west-central Montana within the historic Philipsburg Mining District. According to Lannister Mining, it has year-round access from Philipsburg, MT on paved and well-maintained gravel roads and is about one hour from Butte, MT.
- How big is the Basin Gulch land package?
- The consolidated land package covers 1,107 hectares, made up of 11 patented claims and 53 unpatented claims. A core of patented mining claims is surrounded by unpatented claims, and Lannister Mining reports that about two-thirds of the property remains unexplored.
- What are the best historical drill results at Basin Gulch?
- Lannister Mining’s highlighted historical intersections include 1.8 g/t Au over 162 meters from surface, 0.66 g/t Au over 326 meters from surface, 3.2 g/t Au over 72 meters from surface, 156 g/t Au over 3 meters, and 25 g/t Au over 14 meters. These are historical results, not a current resource.
- Is the Basin Gulch mineralization open?
- According to Lannister Mining, gold-silver mineralization at Basin Gulch is open in multiple directions and at depth, open along strike, and untested regionally. The company says future drilling will concentrate on additional mineralized target areas within the property.
- What is the Philipsburg Mining District known for?
- Lannister Mining describes the Philipsburg district as the area that led the original US silver boom in the late 1800s. Montana is known as the Treasure State, and its first gold discovery occurred in 1852 at Gold Creek, near present-day Garrison.
- Who runs Lannister Mining?
- CEO and Director Jim Greig has more than 25 years of experience and was a founder, President and Director of Thesis Gold (formerly Benchmark Metals). CFO Kelvin Lee has over 15 years of financial management experience. Directors include Mario Vetro, a co-founder of K92 Mining, and geologists Jo Anne Price and Will Randall.
Getting started and common problems
- How should I start researching gold exploration companies?
- Read each company’s technical reports and news releases, not just its presentation. Check whether results are historical or new, how widths are reported, whether a qualified person signed off, and whether a resource estimate exists. SEDAR+ in Canada and EDGAR in the US hold official filings.
- What are the main risks in gold exploration?
- Most exploration projects never become mines. Risks include drilling that fails to confirm earlier results, metallurgy that underperforms, permitting delays, falling metal prices, and repeated financings that dilute shareholders. Treat any early-stage exploration investment as high risk and seek advice from a licensed adviser.
- Can historical drill results be trusted?
- They are useful but need verification. Older programs may have used different sampling, assay or survey methods, and records can be incomplete. That is why a maiden resource usually follows confirmation drilling. Lannister Mining states that Basin Gulch’s resource potential depends on expansion and confirmation drilling of historical intercepts.
- Why do some drill results look extremely high?
- Very high grades over short lengths, such as 156 g/t Au over 3 meters, can reflect coarse or concentrated gold. Resource estimators often cap such assays so they do not overstate grade. Radisson, for example, applies a 60 g/t Au upper cap to individual assays in its O’Brien estimate.
- What is a gram-metre and why does it matter?
- A gram-metre is grade multiplied by interval length, so 1.8 g/t over 162 meters equals 291.6 gram-metres. It puts a thick, lower-grade intercept and a thin, higher-grade one on one scale. It ignores true width and cut-off choices, so treat it as a quick screen only.
- Where can I find Lannister Mining’s investor presentation?
- Lannister Mining posts its investor presentations on the Invest page of lannistermining.com, including a USA presentation dated June 2026. For questions, use the company’s contact page or email IR@lannistermining.com.
- Is this website investment advice?
- No. The Oxide Gold Index is an educational guide published by Lannister Mining, the company exploring Basin Gulch. It explains geology, methods and published figures. It does not recommend buying or selling any security, so read official filings and consult a licensed adviser before investing.
Part of the gold oxide mineralization guide.
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