Crystal your opinion need

Crystal? (Does Fluorite count? I think it's considered a gemstone, but...)

If you actually do specifically mean crystal, I adore NATURAL citrine. Not the heated amethyst stuff, but the natural stuff from mother earth. Next would be dark amethyst. Spirit quartz is nice stuff, too.

Quartz crystals are one of the better crystals. In my opinion the Rutilated Quartz crystal which has all the qualities of normal clear quartz crystal but gives off these properties in high intensities.
Then there is Amethyst, which is another form of quartz crystal that is a great crystal for meditation and channeling energy.
Then there would be Azurite otherwise known as the "stone of Heaven", azurite is great in meditation, and in lore can cure many "polluting" illnesses. Plus its a beautiful stone.

Rose quartz, Opals and Ameryst aregood

I really love sodalite ,lapis lazuli and amazonite .

Look up "The Crystal Awareness Guide" by Legion of Light

You will find everything from Agate to Zircon.

My favorites are:

Bloodstone

Moonstone

Amber

Citrine

Hematite

Jade

Pyrite

Smokey Quartz

Sugilite (Royal Azel)

Variscite

Hope this helps.

i like emerald and tibetan quartz, jet and prehnite are good ones to work with too.

I like me piece of Preseli Blue Stone. It is good for past life regression.

I love selenite. Simple and potent. Selenite is said to be a powerful crystal of psychic communication. It will aid in interaction with the wise ancestors, angles and spirit guides as well as loved ones. It is said to do this telepathically and through divination, with the cosmic records fo wisdom. It is therefore a stone that should be used by mediums and clairvoyants.

Translucent Selenite has a very fine vibration and shall bring clarity of mind, opening the crown and higher chakras while accessing angelic consciousness and higher guidance. Pure Selenite is a link to the light body, helping to anchor it in the earth vibration.

Sidenote: Do not get Selenite wet. Found out the hard way that running water over selenite will cause it to crack and break.

Serpentine, bloodstone, carnelian, and various forms of quartz are really lovely. Lepidolite is also.

I love Rose Quartz, Diamond as it is my birth stone, Lapis Lazuli, and I do not know if this counts, but I love the stone Galena. You however should study up on gems and crystals more before buying some because it looks like to me you don't know much about them. When you learn more about them, you get to see which ones you would actually use based on your magickal workings.