Not the cheapest but definitely one of the prettiest. This would make an impressive gift for Mum or a lovely one! 
Agate is an excellent stone for rebalancing and harmonising body, mind and spirit. It cleanses and stabilises the aura, eliminating and transforming negativity. Agate enhances mental function, improving concentration, perception and analytical abilities.

The crystal pictured is the one you receive 

192.7g

91.3mm x 101.3mm x 15.7mm

All measurements are approximate