Copper Sulfate Pentahydrate Stone Crystal Large crystal · CuSO₄·5H₂O · CAS 7758-99-8
Bought because it sinks. The coarse grade is not a cheaper or lazier copper sulfate — the slow dissolution is the whole functional point, and a fine crystal would do the job badly.
Chelora Chemicals is a copper sulfate stone crystal supplier and sourcing partner serving water treatment, agricultural and industrial buyers across the United States, with the size band and end use agreed before dispatch.
- CAS Number
- 7758-99-8
- Chemical name
- Copper(II) sulfate pentahydrate
- Molecular formula
- CuSO₄·5H₂O
- Molecular weight
- 249.69 g/mol
- Copper as Cu
- 25.45%
- Crystal size
- Large — roughly 8–20 mm
- Traditional names
- Bluestone · blue vitriol
- Transport
- UN 3077 · Class 9 · PG III
- HS Code
- 2833 25
Note: the grade ladder is about dissolution rate, not purity. US suppliers run a continuous size range — large crystal at roughly 8–20 mm, medium around 5–8 mm, small at 1–4 mm, then fine grades graded by mesh at 20, 30, 100 and 200. Every one of them is the same compound at the same assay. What changes is how fast it dissolves and where it ends up: coarse crystals sink and release slowly at depth, fine crystals go into solution quickly. "Stone" and "sugar fine" are trade descriptions rather than standardized sieve specifications, so the actual size band is agreed in writing.
Why size is a functional specification
The same compound behaves differently depending on how big the crystal is. That is the entire reason the grade ladder exists.
Why it matters: a crystal that dissolves at the surface never reaches the bottom algae — coarse grades are specified so the copper arrives where the problem is
What stone crystal is for
Copper sulfate pentahydrate stone crystal is the coarse end of the grade ladder — large blue crystals of roughly 8 to 20 mm, the form historically called bluestone or blue vitriol. It is the same compound at the same 25.45% copper as every other grade. What differs is physics.
A large crystal sinks before it dissolves. That is the point. In pond, lake and reservoir treatment the target is often bottom-growing algae, and a fine crystal that dissolves at the surface simply never gets there. The same slow-release behavior is why coarse grades are used in irrigation ditches, where the crystal has to keep working as water flows past, and in sewer root control, where persistence matters more than speed.
Where the coarse grade is the right choice
- Bottom-growing algae in ponds, lakes and reservoirs — the copper has to reach the bottom undissolved.
- Irrigation ditches and flowing water, where slow release keeps the treatment working as water passes.
- Root control, where persistence matters more than how quickly it goes into solution.
- The fine grade if you are making up solutions: sugar fine crystals.
Handling character
Copper sulfate causes serious eye damage and is a Class 9 dangerous good. Full detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | Blue crystals |
| Copper sulfate pentahydrate | Per agreed specification |
| Copper as Cu | 25.45% theoretical |
| Crystal size | Roughly 8–20 mm, per agreed band |
| Moisture / free water | Per grade specification |
| Water insolubles | Per agreed specification |
Important: the figures above are indicative of commercial material and are offered for planning only. The batch certificate of analysis is the governing document.
| Property | Value |
|---|---|
| Physical state | Blue triclinic crystals |
| Molecular weight | 249.69 g/mol |
| Copper as Cu | 25.45% theoretical |
| Water solubility | Freely soluble |
| Density | ≈ 2.28 g/cm³ |
| Behavior in dry air | Slowly effloresces, losing water |
| Behavior in damp air | Cakes |
Physical constants compiled from public reference data for CAS 7758-99-8 and rounded for readability. All crystal size grades share the same chemistry and assay; they differ in dissolution rate and handling. Treat the table as orientation, not as a specification.
Where US industry uses the coarse grade
Water treatment above all, then root control and agriculture.
Pond, lake & reservoir algae control
The dominant use. Broadcast crystals sink and release copper at depth, where bottom-growing algae actually are.
- Size band agreed in writing
- Pesticidal use needs EPA registration
- Consistent crystal size lot to lot
Irrigation ditches & flowing water
Slow release keeps the treatment working as water flows past, which a fast-dissolving grade cannot do.
- Coarse band specified
- Bulk and bagged supply
- Documented traceability
Sewer & drain root control
Persistence matters more than dissolution speed, so the coarse crystal is the conventional choice.
- Slow-release behavior
- Pack sizes to suit
- Registration sits with the registrant
Agriculture & animal husbandry
Used in footbath and nutritional applications and as a soil copper amendment, where a slower-dissolving form suits.
- Feed-grade documentation on request
- Low heavy metals on request
- End use confirmed before quoting
Industrial & mining
Electroplating, mining flotation and leather processing take copper sulfate in various sizes depending on the dissolution system.
- Size matched to your system
- Non-pesticidal import route
- Bulk supply available
Import & compliance coordination
End use decides the route: pesticidal uses need a Notice of Arrival and an EPA-registered product; industrial uses do not.
- End use confirmed before quoting
- UN 3077 documentation prepared
- Broker coordination on request
Delivered to US plants and ports
We ship copper sulfate stone crystal to nominated delivery points across the United States. The regions below are destinations we serve — Chelora Chemicals is a sourcing and supply partner, not a US manufacturer, and does not hold US stock.
Gulf Coast
The largest US chemical cluster, and the usual entry point for bulk consignments.
- Houston & Galveston, TX
- New Orleans & Baton Rouge, LA
- Mobile, AL
Northeast
Container and bulk delivery into the mid-Atlantic and New England manufacturing belt.
- Newark & Elizabeth, NJ
- Philadelphia, PA
- Boston, MA
Southeast
Port-side delivery for the Carolinas, Georgia and Florida processing plants.
- Savannah, GA
- Charleston, SC
- Jacksonville, FL & Norfolk, VA
Midwest & Great Lakes
Inland rail and truck forwarding from the nearest coastal port to the industrial Midwest.
- Chicago, IL
- Detroit, MI
- Cleveland & Columbus, OH
West Coast
Pacific routing for West Coast processors and formulators.
- Los Angeles & Long Beach, CA
- Oakland, CA
- Seattle & Tacoma, WA
Southwest & Mountain
Inland delivery to interior states, forwarded from the Gulf or Pacific gateway.
- Dallas–Fort Worth, TX
- Phoenix, AZ
- Denver, CO
Importing into the United States
Copper sulfate stone crystal is a TSCA-regulated chemical substance. Under TSCA section 13 the importer of record, or its authorized agent, must certify to US Customs and Border Protection that each shipment either complies with TSCA or is not subject to it. We confirm the substance's TSCA Inventory status and agree in writing who files that certification before the first consignment moves.
Which party carries that duty follows the Incoterm. On FOB, CFR or CIF terms it is usually the US buyer; on DDP terms it can be the seller or its agent. Safety data sheets and labels are supplied to OSHA's updated Hazard Communication Standard, and the UN 3077 Class 9 transport documentation is prepared before booking.
| Item | How it works |
|---|---|
| Delivery points | Any nominated US plant, terminal or port of discharge |
| Incoterms quoted | FOB · CFR · CIF · DDP |
| Importer of record | Agreed in writing before the first shipment |
| TSCA certification | Section 13 positive certification filed at entry |
| Documentation | Batch COA, SDS, packing list, certificate of origin |
| Pack formats | 25 kg bags or bulk bags |
Note: regional coverage describes where we deliver, not where we hold inventory. Lead time depends on producer scheduling and ocean transit to your nominated US port — we confirm both in the quotation.
How we supply copper sulfate stone crystal
Chelora Chemicals is a copper sulfate supplier and sourcing partner, not a manufacturer. On this line the specification that actually matters is crystal size, because every grade is chemically identical and the size is what decides whether the product works where you put it.
We place your order with whichever qualified producer best matches your size band, your price point and your delivery window, and confirm the US import and FIFRA position before booking.
We will also tell you when a finer grade is the right answer. If you are making up a solution or a Bordeaux batch, stone crystal is the wrong product and will cost you dissolving time.
- Size band agreed in writing, not left to "coarse". "Stone" is a trade description rather than a standardized sieve spec, and the band decides whether the product works.
- End use confirmed before quoting. Copper sulfate has pesticidal, industrial and feed uses with different import routes; the wrong route is a customs problem.
- We will steer you to a finer grade where that is right. For solution make-up or Bordeaux, stone crystal is the wrong tool.
- Moisture-barrier packaging as standard. Copper sulfate effloresces in dry air and cakes in damp air, so the pack is part of the specification.
- UN 3077 documentation prepared before booking. Class 9 on aquatic toxicity grounds; the paperwork is not optional.
- Batch traceability to the producing plant. Full chain of custody documentation on request.
Bagged or bulk bagged
25 kg bags, bulk bags or drums — all to UN 3077 marking and labeling requirements.
25 kg poly-lined bags
Moisture-barrier bags on stretch-wrapped pallets, UN-marked, the standard commercial unit.
500–1,000 kg bulk bags
Liner-fitted bulk bags for water treatment and industrial operations.
Fiber or plastic drums
Sealed drums where extended storage or extra moisture protection is needed.
1 kg · 5 kg sealed packs
Small sealed packs to your approved label artwork where you hold a registration.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with dangerous goods documentation filed before booking.
Trial / sample quantities
Small packs dispatched for dissolution and dosing trials before a commercial order.
Serious eye damage and a Class 9 good
Copper sulfate is harmful by ingestion and causes serious eye damage, and it is very toxic to aquatic life with long-lasting effects — which is what makes it a Class 9 dangerous good. The summary below is orientation only — the safety data sheet supplied with your specific batch is the authoritative document.
Classified hazards
H302Harmful if swallowed.H315Causes skin irritation.H318Causes serious eye damage.H410Very toxic to aquatic life with long lasting effects.
End use decides the import route, and copper sulfate has unusually many end uses. Where the material is destined for a pesticidal use — algaecide, fungicide, root control — the import is a pesticide import: it requires a Notice of Arrival, EPA Form 3540-1, filed with Customs, and any product sold or applied in the US must itself be EPA-registered under FIFRA, with that registration held by the registrant and never by a raw material supplier. Where it goes to electroplating, mining flotation, leather or another industrial use, a different route applies. Feed use is a separate regulatory question again. Tell us the end use before we quote.
Storage
Store in sealed, moisture-barrier packaging in a cool, dry, covered area away from food, seed and feedstuffs. Copper sulfate pentahydrate slowly loses water of crystallization in dry air and cakes in damp air, so the pack matters — and it matters more the finer the crystal. Keep away from strong bases and from metals it will attack. Bunded or contained storage is advised because of the aquatic hazard.
Handling
Handle with dust control, impervious gloves and tight-fitting eye protection; copper sulfate causes serious eye damage and is harmful if swallowed. Prevent any release to drains, watercourses or soil. Follow the exposure controls set out in the batch SDS.
Transport
Copper sulfate is classified as dangerous goods for transport on the basis of aquatic toxicity, normally shipped as UN 3077, Environmentally hazardous substance, solid, n.o.s., Class 9, Packing Group III. Marked and labeled packaging, a dangerous goods declaration and compliant documentation are required. We confirm and document the classification for your specific grade, packaging and destination before booking.
Every batch, documented
We verify documentation before dispatch so there are no surprises at your incoming-goods bench.
Specification agreed
Crystal size band, copper assay, moisture and end use confirmed before order placement.
Producer batch testing
The producing plant tests each batch against the agreed specification before release.
Documentation review
COA, SDS, FIFRA position where pesticidal, and UN 3077 paperwork checked before booking.
Traceable dispatch
Each shipment is traceable to its producing batch, with full chain-of-custody records on request.
How crystal size is produced
Copper sulfate pentahydrate is made by reacting copper or copper oxide with sulfuric acid, then crystallizing the product from solution. Crystal size is set in the crystallizer: slow, controlled cooling with low supersaturation grows large crystals; rapid cooling or high supersaturation nucleates many small ones. The grade ladder that US suppliers offer — large, medium, small, then fine grades at 20, 30, 100 and 200 mesh — is a continuous range out of the same process.
That is worth knowing because it means size is not a purity statement. Every grade is the same compound at the same 25.45% copper. A coarse crystal is not a cruder product, and a fine one is not a purer one. They are the same chemistry packaged by dissolution rate.
One handling consequence runs across all of them. Copper sulfate pentahydrate holds five waters of crystallization, and it slowly effloresces in dry air, losing water and dusting, while in damp air it cakes. Coarse crystals are the most forgiving of both, which is one of the practical reasons the stone grade keeps well in bulk storage.
We do not publish operating process parameters here; this is background only. Full technical documentation accompanies every shipment, and any process-specific detail you need is best confirmed directly with our technical desk.
| Chemical family | Copper(II) sulfate pentahydrate |
|---|---|
| Traditional names | Bluestone, blue vitriol |
| Copper content | 25.45% — all grades alike |
| Size band | Roughly 8–20 mm |
| Why coarse | Sinks before dissolving; acts at depth |
| Wrong for | Solution make-up and Bordeaux batches |
The copper sulfate range and the coppers it feeds
The other copper sulfate grades, the Bordeaux family it supplies, and related coppers.
Copper sulfate stone crystal, answered
Why would I buy the coarse grade rather than a fine one?
Is stone crystal a different purity from fine grades?
What size is "stone" exactly?
What is bluestone?
Can I use it to make Bordeaux mixture?
How should it be stored?
Is copper sulfate hazardous?
Can I import this into the United States?
Do you supply copper sulfate stone crystal in the United States?
Do you manufacture this yourself?
Get a quote on copper sulfate stone crystal
Tell us the size band you need and the end use — the first decides whether the product works, the second decides the import route. Send pack format and US delivery point with it and we will quote firm.