A guar or a guar derivative powder having a D.sub.50 particle size of less than 40.mu. which reaches at least 70% hydration within 60 seconds at about 70 degrees F., is disclosed. The powder can be used in applications such as drilling fluid; fracturing fluid; gravel packing fluids; completion fluid; animal litter; explosive; foodstuff; paperstock; floor covering; synthetic fuel briquettes; water thickener for firefighting; shampoo; personal care lotion; household cleaner; catalytic converter catalyst; electroplating solution; diapers; sanitary towels; super-adsorbent in food packaging; sticking plasters for skin abrasions; water-adsorbing bandages; foliar spray for plants; suspension for spraying plant seeds; suspension for spraying plant nutrients; flotation aid; and flocculent.