Talc is a nat­ur­al min­er­al known for its soft­ness, smooth­ness, and abil­i­ty to absorb mois­ture. It is a sil­i­cate min­er­al com­posed of mag­ne­sium, sil­i­con, and oxy­gen. Talc has a unique com­bi­na­tion of prop­er­ties that make it use­ful for var­i­ous indus­tri­al and con­sumer appli­ca­tions. Its crys­tal struc­ture is lay­ered, which gives it a greasy or pearly feel to the touch. Its col­or ranges from white to green­ish, some­times gray­ish. It forms platy, flaky, or mas­sive aggre­gates.

Talc forms under medi­um-tem­per­a­ture meta­mor­phic con­di­tions (300–400 °C) as a result of the trans­for­ma­tion of min­er­als in rocks rich in mag­ne­sium and iron. It can also form through hydrother­mal alter­ation of ultra­ba­sic rocks, often in asso­ci­a­tion with chrome­spinelides, mag­ne­sium car­bon­ates, and cal­cite. In addi­tion, it devel­ops at the con­tact of dolomites with intru­sive or vol­canic rocks under con­tact-meta­so­mat­ic con­di­tions. It is com­mon­ly asso­ci­at­ed with dolomite, chryso­lite, acti­no­lite, tour­ma­line, mag­netite, pyrox­enes, and amphi­boles.

Talc is includ­ed in the list of min­er­als of nation­al impor­tance, approved by Res­o­lu­tion of the Cab­i­net of Min­is­ters of Ukraine No. 827 of Decem­ber 12, 1994, as elec­tri­cal and radio-tech­ni­cal raw mate­ri­als.

Talc is known for its unique set of phys­i­cal prop­er­ties, which make it suit­able for a wide range of indus­tri­al, com­mer­cial, and con­sumer appli­ca­tions.

• Crys­tal struc­ture: Talc crys­tals con­sist of thin sheets or lay­ers of mag­ne­sium, sil­i­con, and oxy­gen atoms arranged in a hexag­o­nal struc­ture. These lay­ers are weak­ly bond­ed and eas­i­ly slide over one anoth­er, giv­ing talc its char­ac­ter­is­tic soapy feel and allow­ing it to cleave eas­i­ly into thin sheets.
• Col­or and appear­ance: Talc can range from white to pale green, gray, or even col­or­less. Its sur­face typ­i­cal­ly has a pearly or greasy lus­ter.
• Hard­ness (Mohs scale): Talc is the soft­est min­er­al on the Mohs scale, with a hard­ness of 1, mean­ing it can be eas­i­ly scratched by hard­er mate­ri­als, includ­ing a fin­ger­nail.
• Ther­mal sta­bil­i­ty: Talc is rel­a­tive­ly sta­ble at high tem­per­a­tures and resis­tant to ther­mal degra­da­tion.
• Chem­i­cal inert­ness: Talc is chem­i­cal­ly inert, mean­ing it reacts very weak­ly with oth­er sub­stances.
• Absorp­tion and adsorp­tion: Talc can absorb mois­ture and oil, which is why it is wide­ly used in cos­met­ics and per­son­al care prod­ucts. Due to its lay­ered struc­ture, it can also adsorb cer­tain sub­stances on its sur­face.

Chemical properties

Talc is a mag­ne­sium sil­i­cate min­er­al with the chem­i­cal for­mu­la Mg₃Si₄O₁₀(OH)₂.

• Hydropho­bic­i­ty: The lay­ered struc­ture and sur­face hydrox­yl (OH) groups make talc hydropho­bic, mean­ing it repels water.
• Insol­u­bil­i­ty: Talc is prac­ti­cal­ly insol­u­ble in water, acids, and bases under nor­mal con­di­tions. This chem­i­cal sta­bil­i­ty allows it to main­tain its prop­er­ties in var­i­ous envi­ron­ments.

Depend­ing on struc­ture and impu­ri­ties, the fol­low­ing types of talc are dis­tin­guished:

• Agalite: Has a fibrous struc­ture. The crys­tal fibers are arranged almost par­al­lel, in one direc­tion.
• Min­neso­taite: The pres­ence of iron (which replaces mag­ne­sium) gives it a brown­ish col­or.
• Steatite: Char­ac­ter­ized by a dense struc­ture. It is also known as soap­stone.
• Willem­seite: Due to the pres­ence of nick­el, it has a blue or green­ish col­or.
• Noble talc: A translu­cent, high-den­si­ty stone that is well-suit­ed for pro­cess­ing.
• Talc-chlo­rite: Con­tains chlo­rite min­er­als.

Based on par­ti­cle size, talc is clas­si­fied into talc pow­der, micro­talc, and coarse-ground talc.

Talc is the main min­er­al of talc ores. The largest reserves of talc and talc stone in West­ern coun­tries are con­cen­trat­ed in the USA, France, Italy, Aus­tria, Nor­way, and India, with the USA alone esti­mat­ing reserves at about 90 mil­lion tons. In Ukraine, the most sig­nif­i­cant deposits dis­cov­ered in the late 20th cen­tu­ry include the Veselyanske talc-mag­ne­site deposit (explored reserves exceed 130 mil­lion tons), the Prav­dynske talc-mag­ne­site deposit (105 mil­lion tons), and the Sukhokhutir area in the Dnipropetro­vsk region (75 mil­lion tons). A by-prod­uct of ore ben­e­fi­ci­a­tion is nick­el-cobalt con­cen­trate.

Well-known glob­al talc deposits include: Sobotin (Czech Repub­lic), Göpfers­grün (Bavaria), Lob­s­dorf and Zöblitz (Sax­ony, Ger­many), Grodziszcze (Poland), Ziller­tal (Aus­tria), Hos­pen­tal (Switzer­land), Bri­ançon (France), Gud­brands­dal (Nor­way), Madoc (Cana­da), and Prov­i­dence (USA).

In indus­try, not only pure talc is used, but also talc-bear­ing rocks: tal­cites con­tain­ing more than 70% talc and talc stones con­tain­ing 35–70%. Depend­ing on min­er­alog­i­cal com­po­si­tion and tech­no­log­i­cal prop­er­ties, talc-chlo­rite, talc-car­bon­ate, talc-mag­ne­site, and oth­er rock types are dis­tin­guished. Talc stone is also known as soap­stone (USA), steatite, or soap­stone, as well as “pot stone” in Ukraine and “fat stone” in Ger­many.

In open-pit talc min­ing, large-scale exca­va­tors are used to increase extrac­tion rates and ensure suf­fi­cient raw mate­r­i­al sup­ply. Work­ers accu­rate­ly deter­mine the direc­tion of talc veins through detailed explo­ration, enabling the extrac­tion of high-qual­i­ty ore.

Pre­lim­i­nary sort­ing sep­a­rates blocks of talc, fine par­ti­cles, and waste based on qual­i­ty. Extract­ed talc can be puri­fied by dry or wet meth­ods. Dry pro­cess­ing is used for high-qual­i­ty deposits, while wet pro­cess­ing is applied to low­er-qual­i­ty ores. Today, the indus­try main­ly uses dry pro­cess­ing to pro­duce ultra­fine talc pow­der, while wet pro­cess­ing is rarely used. Ben­e­fi­ci­a­tion is main­ly car­ried out through froth flota­tion, some­times com­bined with mag­net­ic sep­a­ra­tion.

Talc is a ver­sa­tile min­er­al with a wide range of indus­tri­al appli­ca­tions due to its unique phys­i­cal and chem­i­cal prop­er­ties:

• Cos­met­ics and per­son­al care: Absorbs mois­ture, reduces fric­tion; used in pow­ders, blush­es, and eye­shad­ows to improve tex­ture and appli­ca­tion.
• Phar­ma­ceu­ti­cals: Used as an excip­i­ent and filler in tablets; improves pow­der flow and swal­low­ing.
• Plas­tics and poly­mers: Enhances mechan­i­cal prop­er­ties, increas­es stiff­ness and impact resis­tance of ther­mo­plas­tics, and reduces pro­duc­tion costs.
• Paper and pulp: Used as a filler to improve opac­i­ty, bright­ness, smooth­ness, and tone con­trol.
• Ceram­ics and paints: Improves fir­ing prop­er­ties, reduces shrink­age, enhances glaze adhe­sion, and increas­es opac­i­ty.
• Auto­mo­tive indus­try: Used in plas­tic and rub­ber inte­ri­or com­po­nents due to strength and heat resis­tance.
• Adhe­sives and sealants: Improves vis­cos­i­ty, adhe­sion, and process­abil­i­ty.
• Con­struc­tion mate­ri­als: Enhances weath­er resis­tance, fire resis­tance, and qual­i­ty of ceram­ic tiles.
• Agri­cul­ture: Used as a car­ri­er in pes­ti­cides to improve adhe­sion of active sub­stances to plants.