C.B.D. Minerals – Cali Basalt

Norcal’s Finest Remineralizing Rock Dust: Igneous Basalt. The gold standard of rock dusts for remineralization. We are pleased to offer this primary magma on the west coast. Macro and micro elements in good proprtion. Low metals, high magnetic response. A BEST rock dust for remineralization by definition. (View C.B.D. Minerals Analysis…)


C.B.D. Minerals – California Basalt Deposit (Vintage Stone Flour)


Rock Dust Local has spent nearly 25 years evaluating and working with rock dusts from all over North America. After this length of time they have determined that the best rock dust for soil remineralization are Basalts and Metamorphic and Sedimentary types because of the rich diversity of minerals contained in these volcanic geologic materials.

They even created an acronym for their definition of BEST: “Broad Elemental Spectrum Tectonic”.  Broad Elemental Spectrum refers to the rock dust having a broad spectrum of desired minerals for soil remineralization. C.B.D. Minerals is one the ideal basalts for this purpose because of this analysis(C.B.D Minerals Analysis…). Tectonic ultimately refers to earth shaping forces. All of these are required to make the best rock dust.


C.B.D. Minerals – California Basalt Deposit 34LBS


C.B.D. Minerals – California Basalt Deposit 17LBS



Rock Dust FAQs:

Q: What is remineralization?

A: Remineralization is the utilization of natural broad elemental spectrum rock dust materials for the purpose of renewing the mineral content of soils and other growing media.

Q: How Much Rock Dust Do I Use?

A: Application rates will vary according to usage, soil type and condition. Field trials indicate that a direct benefit exists between application rate and increase harvest weight starting at very low rates and running up through very high rates, up to 250% increase in harvest weight over the controls. (Goreau et. al, New Harmony Farm 2012) Rock dust for remineralization has traditionally been utilized at very high rates, up to 10 tons per acre. However the science indicates that low rates of high value rock dust containing a highly micronized fraction will have immediate and lasting benefits. With this in mind, usage protocols can be built around management practice, economics, size of growing area, type of crop etc. For professional soil management practices use of soil tests, careful analysis of rock dust geochemistry and mineralogy, identifying ‘limiting factors’ in current growing practices and a careful comparison of available rock dusts for targeted use and annual usage rates can provide measurable benefits.

For a less scientific approach, a liberal application of the California Basalt Deposit C.B.D. rock dust in a suitable gradation works. The risk of ‘burning’ or damaging crops within maximum application rates is virtually impossible.

For maintaining foundation fertility after initial remineralization; Very low rate foliar applications or fertigation of 5-25 lbs/acre of the highly micronized gradations will provide nutrient and energy loads once or more times per season. 1 – 2 tons/acre can be used as a top dressing or incorporated during tillage every 1 to 3 years depending on production and crop rotation.  That converts to 5 – 10 lbs./100 square feet. Seven year rotation cycles can also be integrated with rock dust applications over fallowed ground.

We strongly recommend the use of aqueous solutions of micronized minerals and inoculants for foliar, fertigation and drenching during the growing season.  The rock dust minerals in
direct-to-ground applications provide the foundation of fertility upon which good intensive nutrient dense management practices rest.

Q: When is the best time of year to apply rock dust?

A: Spring tillage is traditional but fall applications can be even better. Apply rock dust powders with other amendments at the same time.

Fall tillage or top dressing applications are also excellent as the rock dust incorporated in the fall assimilates over the winter and is available during the spring growing season. I.e., Apply with planting of overwintering tubers such as garlic, broadcast over hay land, or pasture.  Rock dust can be applied whenever cover crops are tilled in preparation for new plantings.

The charge of micronized C.B.D.  Minerals will stimulate microbial populations and make the nutrients more available to the new crop.  Micronized rock powders can be suspended in water for ‘fertigation’ and foliar use during the growing season. Top dressing or side dressing can also be done during the season at any time.

Q: Can I use rock dust in making compost?

A: Yes! Good results have been achieved using 20-25lbs micronized high silica, calcium rich rock dusts/ cubic yard of compost raw material. This is an excellent way to assimilate the minerals within the biologic system in the soils, making the nutrients available to the plants. True Remineralized compost will be built with rock (not just mixed with it post digestion). There is a difference!

Q: How does rock dust compare to conventional synthetic fertilizers?

A: There is little comparison. Many synthetic petroleum derived fertilizers are acid salts or soluble sulfates of a very narrow elemental spectrum, often containing a single elemental nutrient in combination with Chlorine or Sulfur.

Chemical fertilizers are usually a combination of three elements; N, P, and K (Nitrogen, Phosphorus and Potassium) delivered in soluble form.  The broad elemental spectrum rock dusts contain a naturally occurring distribution of macro and micro nutrients delivered in mineral form, are generally insoluble crystaline structure and rely on weathering and an active soil biology consisting of beneficial bacteria and fungi to assimilate the mineral elements, making the nutrients available to the plants as needed.

Highly micronized fractions of rock dust blends are immediately available to biologic systems and are highly effective in building amino acids and enzymes critical for biologic systems. There is little or no nitrogen in most rock dust materials although essential elements for fixing nitrogen in soils such as Molybdenum and Vanadium are present in many high quality rock dusts.

The use of fixed carbon and humic sources are encouraged as companion materials to the broad elemental spectrum rock dusts to help build soil biology and regulate the uptake of essential nutrients in plants.

Soil remineralization is a method of encouraging a natural, sustainable and self regulating growing environment which promotes long term and sustainable fertility.

Q: Is there any way to measure the effectiveness of rock dusts?

A: Yes. Annual soil testing should show improvements in both available nutrients and overall nutrient density in soils. Additionally, Brix meter readings should improve, indicating higher sugar and mineral content in plants. Tissue analysis of produce and forage should indicate increased mineral and nutrient value. Overall improvement in plant vigor should follow the assimilation of minerals in the rock dust.

Q: Do I still need to use fertilizers when I apply rock dusts?

A: Initially soils which are seriously depleted of certain mineral nutrients and microbial populations will need to be restored with a combination of macro and micro nutrients, inoculations and fixed carbon sources in addition to the broad elemental spectrum rock dusts.  Thereafter, a reliance on the narrow elemental spectrum fertilizer inputs may diminish with good management, crop rotations, adequate use of humic materials, fixed carbon and applications of broad elemental spectrum rock dusts. Most rock dust materials cannot be considered fertilizers in the conventional definition of high soluble doses of N-P-K.

These major nutrients will still need to be managed whatever practice is being employed. Rock dusts for remineralization are used to establish a foundation of fertility that good nutrient management rests upon.