Here are some examples of crystal colour categories and their meanings:
Silver/Grey tones represent transformation, change and sometimes invisibility.
Black tones offer protection, they are grounding and act as detoxifiers.
Brown gems can be used when you need to feel centred, they are purifying and are great for cleansing rituals.
Pink crystals represent love, they help with feelings of unease and apprehension.
Peach tinged stones are invigorating, and they revitalise in a gentle way.
Red stones are energising in a more stimulating way, galvanising you into action.
Orange crystals enhance your creative abilities, you will approach tasks with vibrancy and they leave you self-assured.
Yellow gems bring abundance into your life, they represent wealth, but also clarity of thought.
Green tones represent empathy and kindness, they provide calm and are restorative,
Turquoise stones are all about intuition, and as such used properly they let you attain peace and serenity.
Blue crystals are for communication – express yourself!
Purple tones, including lilac and lavender connect you to a higher power, they are the colour of insight, perception and spiritual awareness.
White gems represent everything that is pure, innocent and virtuous.
Clear stones are about a higher consciousness, they are both energising and purifying.
A crystal made up of more than one colour are stimulating, exhilarating – all about the possibilities.
You might not think that the shape of a crystal makes much difference, but in fact the shape impacts the way light moves through the gem and as such the energy that it provides.
Here are some meanings of the different shapes available:
A square crystal is all about fusing energy.
An egg shape will focus and release energy.
When a crystal is shaped like a ball, it represents equal energy all around.
When a gem is formed as a cluster it will radiate energy equally in all directions.
A Geode is when a small cavity in rock is lined with crystals, this provides a slow releasing energy that is both preserved and intensified.
Some stones are pointed, this can be useful in crystal healing, energy can be drawn in or out depending on the direction of the point.
When a stone has a point at both ends, it is called ‘double terminated’, in these cases energy is produced and released in two directions.
Ref: The Little Book of Crystals, Judy Hall