Hardness and toughness
The Mohs scale is the most commonly used scale used to measure gem and mineral hardness. Corundum (ruby and sapphire) are relatively hard gemstones —9 on the Mohs scale. They have excellent toughness and no cleavage, which is a tendency to break when struck. This makes them a great choice for rings and other mountinsubject to daily wear.

Stability
Rubies are stable under normal wearing conditions, which means that they’re resistant to the effects of heat, light, and common chemicals. Filled or dyed ruby stones can be affected by the slightest mild acids like lemons.

Cleaning
Warm soapy water is always safe. Ultrasonic and steam cleaners are usually safe for untreated, heat-treated, and lattice diffusion treated ruby stones. Filled, or dyed gemstones should be cleaned with the help of a damp cloth.

Although some people take gemstones/jewelleries to a reputed brand or an individual to have it professionally cleaned, ruby gemstones can be easily be cleaned at home too. 

1.     In a bowl place some warm water, and some mild detergent or a small amount of ammonia
2.   Place the ruby stone in the solution for a few minutes
3.   Remove the jewellery from the bowl and clean gently with the toothbrush using the liquid from the bowl. 
4.   Wash your ruby under clean warm water until any residue of soap is removed.
5.   Rinse and dry with a clean soft cloth.

It is wise to have ruby stones professionally cleaned and examined once every year or so.

Storage
Store your ruby pieces separate from the rest of your jewellery as they can easily scratch other stones and metals or be scratched by any other gemstones in your collection.