Reviewed September 2026 against Intratec commodity pricing, USGS Mineral Commodity Summaries, and Benchmark Minerals Intelligence.

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Battery-grade lithium carbonate averaged $11,000 per tonne globally in November 2025, per Intratec commodity pricing, while lithium hydroxide spot prices CIF Asia reached $18,750 per tonne as of September 2, 2026, per Benchmark Minerals Intelligence. A one-carat round natural diamond priced at $4,407 per carat in December 2025 on the Rapaport Diamond Price Index. Phosphoric acid 85% in the United States averaged $984 per tonne in November 2025, per Intratec, with North American delivered Florida pricing at $996.67 per tonne for Q4 2025, per Procurementresource. None of these numbers hold still — this page tells you where each one comes from, how often it updates, and how to pull a fresher one yourself.

Lithium Carbonate Price Per Tonne: Spot, Contract, and Grade Spread

Two grades of lithium carbonate trade at meaningfully different prices, and conflating them is the most common reason a quoted “lithium price” looks wrong to someone checking a different source. Battery-grade lithium carbonate averaged $11,000 per tonne globally in November 2025, according to Intratec’s primary commodity pricing service. Industrial-grade lithium carbonate — the lower-purity form used outside batteries, in glass, ceramics, and grease — averaged $10,400 per tonne in the same November 2025 period, also per Intratec.

A year earlier, the U.S. Geological Survey’s Mineral Commodity Summaries 2025 recorded China spot-market battery-grade lithium carbonate at $9,400 per tonne for November 2024. That’s the U.S. government’s own reference point, and it sits below the November 2025 Intratec figure — a real year-over-year increase in the battery-grade spot price, not noise.

The swings get larger once you look across a full cycle. Trading Economics data (sourced from Shanghai Metals Market and related trading platforms) shows battery-grade lithium carbonate at the equivalent of $8,000 per tonne ($8/kg) in May 2025. Benchmark Minerals Intelligence then tracked the same battery-grade material rising to the equivalent of $25,000 per tonne ($25/kg) by May 2026. That’s a more than threefold move in twelve months, and it’s the reason any single-point “the lithium price is $X” claim is close to meaningless without the month attached.

Spot and contract prices diverge further apart during periods like this. Battery manufacturers and automakers with multi-year offtake agreements are typically insulated from a run like May 2025 to May 2026 for the volumes those contracts cover — but any tonnage bought on the spot market during that window paid the full swing. If you’re pricing a real purchase, ask your supplier explicitly whether the quote is spot or contract, and for which month.

Lithium Hydroxide and the Metal Price Gap

Lithium hydroxide is the second major battery-grade lithium chemical, used preferentially in high-nickel cathode formulations. USGS Mineral Commodity Summaries 2025 recorded battery-grade lithium hydroxide at $9,900 per tonne on the China spot market in November 2024 — close to, but not identical to, the carbonate price for the same month ($9,400/tonne). By September 2, 2026, Benchmark Minerals Intelligence had battery-grade lithium hydroxide, spot CIF Asia, at $18,750 per tonne.

On lithium metal specifically — pure lithium metal rather than a lithium compound — the research for this article found no tonne-denominated commodity quote in USGS, Intratec, Benchmark, or Trading Economics data. Lithium metal is rarely traded or priced in bulk per-tonne form on public commodity platforms; it shows up instead in gram or per-unit pricing for specialty and battery-anode applications, and USGS’s own commodity summary reports carbonate and hydroxide, not metal, as its benchmark forms. If you need a lithium metal price specifically, the more reliable path is a direct quote from a metal supplier (e.g., Livent, Albemarle, or a metals trading desk) for the exact purity and form you need, since no standardized public index exists for it the way one does for carbonate and hydroxide.

Diamond Price Per Carat: The Rapaport Index Explained

A 1-carat round natural diamond, per the U.S. natural diamond price index tracked by the Rapaport Diamond Price Index, priced at $4,407 per carat in December 2025. Rapaport is the industry-standard reference for polished diamond pricing and has published this index weekly for decades; the figure above is specific to round, 1-carat, and to the December 2025 update — carat weight, shape, color, clarity, and cut all move the number independently, sometimes by more than the month-to-month index change itself.

No U.S. government agency publishes a diamond commodity price series comparable to USGS’s lithium or copper data — USGS tracks industrial diamond production and reserves, not polished retail or wholesale carat pricing. That means the Rapaport Index (and retailer-published charts built on it, such as those aggregated by thediamondprice.com) is effectively the primary public benchmark for “current diamond price per carat,” rather than one source among several government ones.

Because Rapaport updates weekly, a December 2025 figure is already a snapshot, not a running number. If you’re pricing a purchase or an insurance valuation now, go to the current week’s index rather than anchoring to the figure above — see the refresh method in the “How to Verify” section below.

Phosphoric Acid 85% Price Per Ton in the US

Phosphoric acid at 85% concentration — the standard commercial grade used in fertilizer manufacturing, food processing, and industrial applications — averaged $984 per tonne in the United States in November 2025, per Intratec’s commodity pricing service. A regional variant of the same period, North American material delivered to Florida (the center of U.S. phosphate processing), averaged $996.67 per tonne for Q4 2025, per Procurementresource. Procurementresource’s broader 2025 average across the year came in at $1,050 per tonne for the stabilized range.

Those three figures — $984, $996.67, and $1,050 per tonne — aren’t in conflict; they’re answering three different questions: a single-month U.S. average, a Q4 Florida-delivered average, and a full-year range. If you’re budgeting a purchase, the Q4 2025 Florida-delivered figure is the closest proxy to what a U.S. buyer near the Gulf phosphate belt would actually pay landed, while the November 2025 Intratec number better reflects a broader national spot average.

One caveat worth stating plainly: Intratec’s phosphoric acid data combines 85% and 75% concentrate grades in its published series, and no source used for this article isolates a clean 85%-only premium over 75%. If your purchase specification depends on that exact spread, get it directly from your supplier’s quote sheet rather than backing it out of index data — the gap isn’t published anywhere checked for this article.

Price Comparison Table: Four Commodities, One Page

These four commodities don’t share a market, a unit convention in every case, or a price driver — but a buyer or analyst tracking more than one of them benefits from seeing the sourcing side by side. Every row below is a figure from this article, with its exact vintage and source.

Why These Four Prices Move Independently

Lithium, diamonds, and phosphoric acid answer to three unrelated sets of forces, and treating them as a single “minerals market” story is where a lot of commentary goes wrong.

Lithium: Battery Demand and Refining Capacity

• EV and grid-storage demand growth is the primary pull on battery-grade carbonate and hydroxide, and it’s the reason battery-grade consistently prices above industrial-grade in the same Intratec and USGS series.
• Refining bottlenecks, not just mine supply, drive short-term spikes — converting spodumene or brine concentrate into battery-grade chemical requires capacity that doesn’t scale as fast as new mine output.
• Geographic concentration in Australia, Chile, Argentina, and China means a single country’s export policy or plant outage shows up in the global spot number within weeks.

Diamonds: Retail Demand and Lab-Grown Substitution

• Natural diamond pricing responds to jewelry retail demand cycles and to the ongoing price competition from lab-grown diamonds, which the Rapaport Index tracks as a separate, lower-priced series.
• No mining-supply shock comparable to lithium’s refining bottlenecks moves diamond pricing the same way — the constraint is closer to demand and grading than to extraction capacity.

Phosphoric Acid: Fertilizer Season and Natural Gas

• Phosphoric acid production is energy- and sulfur-intensive; input costs (particularly sulfur and ammonia, where relevant to downstream fertilizer blends) move the acid price independently of any mineral exploration cycle.
• U.S. fertilizer-season demand (spring planting, then fall application) creates a seasonal pull that shows in the delivered-Florida figures Procurementresource tracks by quarter.

Landed Cost Calculator

Use this to convert any per-tonne or per-carat quote you’re given into a total landed cost for your actual purchase quantity, with freight and a percentage markup or discount layered on top of the base price you enter.

Assumes a flat per-unit freight/handling figure and a single percentage adjustment for contract vs. spot terms; it does not account for currency hedging, insurance, storage, or grade-based quality premiums, which should be added from your own supplier quote.

Where Agriculture, Mining, and These Commodities Intersect

Phosphoric acid is the direct link to agriculture: it's the primary intermediate in manufacturing phosphate fertilizers (DAP, MAP, and related products) used across U.S. row-crop and specialty agriculture. A $984–$1,050 per tonne range for 85% acid in late 2025 feeds directly into fertilizer input costs that farm operations budget against each planting cycle — tracking this index alongside USDA's own fertilizer price series gives a more complete picture than either alone.

Lithium's link to agriculture and land management is more indirect: battery-powered equipment procurement (electric tractors, irrigation controllers, and site equipment) is priced against the same lithium carbonate and hydroxide costs covered above, and land near lithium brine or hard-rock extraction sites faces the water-management and land-use planning questions common to any resource-extraction neighbor. Diamonds have no meaningful agricultural linkage; they're included here strictly because of the search demand behind this page, not because of a shared supply chain with lithium or phosphoric acid.

For operations evaluating land near any mineral development — lithium, phosphate rock, or otherwise — greenfield mineral project activity is a leading indicator worth tracking before prices show up in a spot index.

Satellite Mineral Detection: Finding Supply Before It's Priced In

Farmonaut's satellite-based mineral detection platform applies Earth observation and AI-driven analysis to identify prospective mineral zones — including lithium-bearing pegmatite and brine targets — without ground disturbance. For an industry where refining bottlenecks (not just mine supply) drive the price swings described above, earlier and cheaper identification of new supply is one of the few levers that affects the underlying constraint rather than just reacting to its price.

The platform's non-invasive approach delivers:

• ✔ Prospect validation across large regions in days rather than months, cutting early-stage field time
• 📊 Up to 85% reduction in early-stage exploration costs versus ground-survey-first approaches
• 🔍 Multispectral and hyperspectral screening for objective mineral targeting
• ⚡ Integration with 3D subsurface mapping to prioritize drilling investment
• 🌱 Zero ground disturbance, supporting ESG-aligned exploration programs

The workflow: submit an area of interest (coordinates or KML), specify target minerals (lithium, diamond-associated kimberlite, phosphate rock, or others), and receive high-resolution maps, georeferenced files, and a technical report. See the full satellite-driven 3D mineral prospectivity mapping overview for methodology detail, or map a site directly at mining.farmonaut.com.

• 🔗 Get a custom quote for your exploration project.
• 🔗 Contact us for technical and commercial queries.

How to Verify These Prices Yourself Next Quarter

Every figure above will be out of date on a different schedule. Here's the exact refresh path for each, so you're not stuck re-Googling from scratch:

1. Lithium carbonate (spot): Benchmark Minerals Intelligence updates its Asia CIF spot quote daily — search "lithium carbonate price today" or go directly to their lithium price page for the current week.
2. Lithium carbonate and hydroxide (US/global reference): Check Intratec's lithium carbonate pricing page, updated monthly, or USGS's annual Mineral Commodity Summaries lithium chapter for the government reference series.
3. Phosphoric acid (US): Intratec updates its phosphoric acid pricing page monthly; for delivered-Florida and regional breakdowns, use Procurementresource's phosphoric acid price trends. USDA AMS also publishes weekly Gulf/NOLA fertilizer reference prices worth cross-checking.
4. Diamonds (per carat): The Rapaport Diamond Price Index updates weekly; retailer-published charts built on it, including thediamondprice.com's diamond price chart, are the most accessible public mirror of the current index for mainstream carat weights and grades.

As a durable check independent of any single index: if a quoted price sits more than roughly 15–20% away from the most recent figure on the relevant source above for the same grade and month, ask the supplier which exchange, region, or grade their number reflects before accepting it — that gap is usually a grade or geography mismatch, not a data error.

FAQ

Summary

Four commodities, four separate markets, and four different refresh schedules: battery-grade lithium carbonate at $11,000/tonne (November 2025, Intratec) and hydroxide at $18,750/tonne (September 2026, Benchmark), a 1-carat diamond at $4,407/carat (December 2025, Rapaport), and phosphoric acid 85% between $984 and $1,050 per tonne across US and Florida-delivered measures (Q4 2025 and full-year 2025, Intratec/Procurementresource). None of these numbers are static, and none of them move together — treating them as one story is how a buyer ends up with the wrong number for their actual purchase.

The durable part of this page isn't any single price: it's the method above for pulling a current one — which index tracks which grade, how often each updates, and what a mismatch between a quote and an index usually means. Bookmark the source links in the verification section rather than this month's figures, and the page keeps working long after these numbers change.