Glau­conite: Char­ac­ter­is­tics, Occur­rence, and Appli­ca­tions

Glau­conite is a wide­spread min­er­al occur­ring in sed­i­men­ta­ry rocks and belong­ing to the class of sil­i­cates (hydromi­ca group). Its chem­i­cal com­po­si­tion is vari­able and depends on the con­di­tions of for­ma­tion. The gen­er­al­ized for­mu­la of glau­conite is:
(K, Na)(Fe³⁺, Al, Mg)₂[(OH)₂(Si, Al)₄O₁₀].

The con­di­tions of its for­ma­tion remain a sub­ject of dis­cus­sion, but it is gen­er­al­ly believed that the min­er­al orig­i­nates main­ly in marine basins dur­ing the process of halmy­rol­y­sis of basalts and pyro­clas­tic rocks, as well as under the influ­ence of hydrother­mal process­es.

Glau­conite is includ­ed in the list of min­er­als of nation­al impor­tance approved by the Res­o­lu­tion of the Cab­i­net of Min­is­ters of Ukraine dat­ed Decem­ber 12, 1994, No. 827, as a raw mate­r­i­al for agro­chem­i­cals and for the pro­duc­tion of min­er­al pig­ments.

• SiO₂ – 45–58;
• Al₂O₃ – 3–22;
• Fe₂O₃ – 0–27;
• MgO – 1,7–4;
• K₂O – 4,0–6,4;
• H₂O – 4–10

Occurrence of Glauconite

In the mid­dle Dni­ester basin, glau­conite-bear­ing rocks are asso­ci­at­ed with Low­er Ceno­man­ian deposits. Quartz–glauconite sands are main­ly dis­trib­uted in the north­west­ern parts of Mid­dle Transnis­tria (the Zbruch Riv­er val­ley and the Dni­ester basin near Zal­ishchyky), where their thick­ness reach­es 1.5 m. In the east­ern regions (Mohyliv Transnis­tria), these sands are thin­ner and local­ly under­lain by sandy lime­stones with glau­conite.

Between the Stu­denyt­sia and Kalius rivers, a sequence of opa­line silicites with glau­conite admix­ture lies on Pale­o­zoic rocks, with thick­ness­es rang­ing from 0.5 to 7 m. Above this occurs a sandy–clayey unit con­tain­ing interbeds of mala­chite-green glauconite–quartz sands with sandy phos­pho­rites and brown iron­stone con­cre­tions (1.5–4.0 m thick).

In the Kalius and Zhvan riv­er basins, sands are replaced by glau­conitic sandy lime­stones, with glau­conite con­tent reach­ing 25%.

All Ceno­man­ian glau­conite-bear­ing sands of Mid­dle Transnis­tria are divid­ed into: glauconite–quartz, opal–glauconite–quartz and quartz–glauconite sands.

• 1. Glauconite–quartz sands – locat­ed at the base of the Low­er Ceno­man­ian sec­tion; most­ly het­ero­ge­neous-grained green sands con­tain­ing up to 50% glau­conite. In south­east­ern Podil­lia they con­tain reworked phos­pho­rites.
• 2. Opal–glauconite–quartz sands – occur in the mid­dle of the Low­er Ceno­man­ian sec­tion; glau­conite con­tent varies from 10 to 30%, giv­ing light green to yel­low­ish-green col­ors.
• 3. Quartz–glauconite sands – found main­ly in the upper part of the Low­er Ceno­man­ian sec­tion and in sandy–clayey stra­ta; typ­i­cal­ly dark green or mala­chite-green with glau­conite con­tent up to 70%.

Glauconite Deposits

The Podil­lian Transnis­tri­an region has been active­ly stud­ied for glau­conite by the State Region­al Geo­log­i­cal Enter­prise Pivnich­ge­olo­gia. In south­ern Khmel­nyt­skyi Region, pre­lim­i­nary explo­ration iden­ti­fied:
Karachaivske Deposit (Vinkivt­si dis­trict) – reserves of about 400 mil­lion tons of sand with 60–70% glau­conite.
Adamivske‑1 and Adamivske‑2 Deposits (Yarmolyntsi dis­trict). Adamivske‑2 reserves are esti­mat­ed at 30 mil­lion tons with up to 50% glauconite.Currently, only Adamivske‑2 is being com­mer­cial­ly devel­oped (LLC NVKP “Ecore­source”).

Fore­cast resources of glau­conite in Mid­dle Transnis­tria are esti­mat­ed at 1–3 bil­lion tons with an aver­age glau­conite con­tent of 50–70%. Deposits occur near the vil­lages of Mat­siorsk, Brailiv­ka, Struha, Kucha, Antoniv, Kru­ti Brody, and oth­ers, at depths of 0.5–16 m with pro­duc­tive lay­er thick­ness­es of 3–16 m.

In Donet­sk Region, glau­conite-bear­ing rocks are most com­mon in the Kalmius–Torets and Bakhmut basins and in the Konka–Yalyn depres­sion, where they are asso­ci­at­ed with phos­pha­tized Upper Cre­ta­ceous deposits. Dur­ing ben­e­fi­ci­a­tion of phos­phate ores, glau­conite con­cen­trate can be obtained as a by-prod­uct. For exam­ple, devel­op­ment of the Osykivske phos­pho­rite deposit may yield up to 1.1 mil­lion tons of glau­conite con­cen­trate suit­able for soil appli­ca­tion.

The Karpivske phosphorite–glauconite deposit (Amvrosi­iv­ka dis­trict) is rep­re­sent­ed by clayey and car­bon­ate sands of the Low­er Ceno­man­ian (4.0–19.2 m thick). Aver­age con­tents of phos­pho­rite – 10.8%? glau­conite – 22.5%. Reserves (C₂ cat­e­go­ry) amount to 2 mil­lion tons, with fore­cast resources of 9 mil­lion tons.

The Mal­okamyshu­vakha com­plex deposit (Kharkiv Region) con­tains phos­pho­rite nod­ules in marl and quartz–glauconite sands. P₂O₅ con­tent ranges from 14.4% to 17.8%. Planned prod­ucts include fine­ly dis­persed chalk, phos­phate flour, enriched glau­conite (80%), high-grade ground lime, and asso­ci­at­ed mate­ri­als such as flint and sand­stone.

Over­all, glau­conite often occurs as an asso­ci­at­ed com­po­nent in phos­phate min­ing (e.g., Osykivske and Zhvan deposits), increas­ing the eco­nom­ic effi­cien­cy of extrac­tion.

Practical Applications

Glau­conite is a mul­ti­func­tion­al min­er­al enriched in potas­si­um, iron, mag­ne­sium, and phos­pho­rus, mak­ing it valu­able as a nat­ur­al fer­til­iz­er. Its cation-exchange and sorp­tion prop­er­ties stim­u­late plant growth and reduce dis­ease inci­dence. One ton of glau­conite can intro­duce approx­i­mate­ly 60 kg of K₂O, 7 kg of P₂O₅ into the soil along with trace ele­ments.

Glau­conite sig­nif­i­cant­ly increas­es crop yields. For exam­ple, appli­ca­tion of 60 kg/ha in Kyiv Region increased bar­ley yield by 44%. Sim­i­lar effects were observed for buck­wheat, oats, maize, and sug­ar beet. Glau­conite fer­til­iz­ers also reduce plant dis­eases, improve prod­uct qual­i­ty and enhance eco­log­i­cal soil recov­ery.

Glau­conite is also used as a min­er­al addi­tive to improve physic­o­chem­i­cal and gran­u­lo­met­ric prop­er­ties of fer­til­iz­ers. Stud­ies by insti­tutes of the Nation­al Acad­e­my of Agrar­i­an Sci­ences of Ukraine has estab­lished that the use of nat­ur­al fer­tilis­ers based on glau­conite increas­es the yield of grain crops by 24–44% and veg­eta­bles by 25–40%.

Glau­conite serves as raw mate­r­i­al for min­er­al paints and pig­ments, adsor­bents, potas­si­um-con­tain­ing fer­til­iz­ers. In the Unit­ed States, potas­si­um salts are extract­ed from glau­conite through chem­i­cal pro­cess­ing, pro­duc­ing by-prod­ucts such as sil­i­ca gel and cement.

Exper­i­ments con­duct­ed by Ivan Franko Nation­al Uni­ver­si­ty of Lviv and the Geot­ech­ni­cal Insti­tute demon­strat­ed its effec­tive­ness in adsorb­ing petro­le­um prod­ucts: a mod­el solu­tion (347 mg/L) treat­ed with glau­conite-bear­ing mate­r­i­al decreased to 1 mg/L after two hours, with each gram adsorb­ing 2.77 mg of hydro­car­bons.

• 1. Ani­mal hus­bandry: Used as a feed addi­tive, reduc­ing the con­tent of heavy met­als in milk and ani­mal blood. Exper­i­ments with the use of glau­conite for min­er­al feed­ing of pigs have shown that the addi­tion­al aver­age dai­ly weight gain is up to 29%.
• 2. Fish farm­ing: Pro­motes the growth of algae bio­mass, enrich­ing it with pro­tein. This opens up oppor­tu­ni­ties for the use of glau­conite in fish farm­ing for grow­ing algae (chlorel­la) for ani­mal feed.
• 3. Land recla­ma­tion: Glau­conite sands effec­tive­ly restore the fer­til­i­ty of dis­turbed lands. At the same time, land fer­til­i­ty is restored 1.5–2.0 times faster, and forests and high yields of peren­ni­al grass­es thrive on them.
• 4. Ecol­o­gy: Absorbs radionu­clides, reduc­ing their con­cen­tra­tion in the envi­ron­ment. Glau­conite sands and glau­conite con­cen­trates from the Karachiyivets and Adamiv­ka deposits were stud­ied at the L.V. Pysarzhevsky Insti­tute of Phys­i­cal Chem­istry of the Nation­al Acad­e­my of Sci­ences of Ukraine with a view to their use in envi­ron­men­tal pro­tec­tion mea­sures in the 40 km zone around the Cher­nobyl Nuclear Pow­er Plant and in oth­er emer­gency sit­u­a­tions.

There­fore, Ukraine’s sig­nif­i­cant reserves of glau­conite are a strate­gic resource for the devel­op­ment of agri­cul­ture, ecol­o­gy and indus­try. Owing to its rich chem­i­cal com­po­si­tion, in par­tic­u­lar its potas­si­um, mag­ne­sium, iron and phos­pho­rus con­tent, glau­conite has great poten­tial as a fer­tilis­er that increas­es crop yields, improves prod­uct qual­i­ty and reduces plant dis­ease rates. The use of glau­conite in ecol­o­gy is par­tic­u­lar­ly impor­tant.

The min­er­al is effec­tive­ly used to cleanse soil and water resources of tox­ic ele­ments and radionu­clides, con­tribut­ing to their eco­log­i­cal restora­tion. Its cation exchange capac­i­ty makes it indis­pens­able for the recul­ti­va­tion of degrad­ed land, the restora­tion of fer­til­i­ty in dis­turbed areas, and the reduc­tion of envi­ron­men­tal pol­lu­tion. Thus, glau­conite is a mul­ti­func­tion­al resource that pro­vides envi­ron­men­tal, eco­nom­ic, and social ben­e­fits, and its active use can sig­nif­i­cant­ly influ­ence the sus­tain­able devel­op­ment of Ukraine.