crystal ball - crystal quartz or obsidian?

I am looking into the purchase of a crystal ball; however, because the best stones are so expensive, I want to make sure I buy the right stone to cleanse and charge for scrying and communication. I am decided between obsidian and crystal quartz (rose or clear).

I want to choose quartz because it has energy specifically strong when ita purpose is divination. i also am familiar with it and know how it feels . . . but i can master obsidian as quickly as it arrives on my doorstep and i want obsidian because it is apparently easier to use because of the black color. it also has protective qualities; and, although i would have to raise more energy to charge it, the end result would be a clearer reading and a safer reading
.. basically just more work and time making it work. the quartz would be faster and kind of easier on my personal energy but harder to see in use.i

for those with knowledge or experience behind crystals or divination with mirrors/crystalballs, what stone would you choose and why?

I think it all depends on which stone you are more comfortable with. Some people, including myself, really resonate with gazing into a clear item for scrying purposes. Others like a dark surface. It's all a matter of preference. I wouldn't think that one stone would take more effort to charge than the other, particularly if you are using something like sunlight, moonlight, or sound.

So if you're able to examine the spheres in person, do that, and then choose the one that clicks with you the most. If you're looking at spheres online, you can still determine which one appeals to you the most strongly, go with that, and you'll know you have made the right choice for you.