yeah they are the size they want to be the obsidian could be knapped further into something but unless you like shards of volcanic glass everywhere best not to.
The obsidian is also a good at absorbing RIFI radio emissions as well as "electromagnetic smog" that comes from electronics.
Now the tumbles these are what i call pocket stones, you can carry them in you wallet or purse or in your pockets.
The citrine NEVER needs cleansing as its one of 5 stones that can be as pure as daylight no matter what you do with it.
Though rinse it with water if it gets dirty.
Amethyst doesn't like to be in sunlight to much as B wave Ultra violet tends to bleach them of its color (something to do with photon emission and refraction of the manganese and iron mixture with in the hexagonal crystalline lattice)
But moon light or nice non-phosphorous soapy water is a good cleaners. And with This years super special full moon coming up take advantage of the unique energy that will sure to occur on the 31st this month.
Ah that's clear quartz, okay then its simply good for all chakras even higher dimensional ones. this one is great to carry around if your feeling glum, or just kinda out of it.
Warning though to much mediation with powerful crystals can leave you feeling a bit... in the clouds so to say and if you want your clarity back your gonna have to ground again.
The blue chalcedony if its natural blue is very pleasant energy similar to rose quartz, if its artificially colored it tends to be a bit off. but for novices its should be okay your not looking for that kick in the pants type crystal anyways those can.. well do a bit of psychological damage to the inexperienced, things like Moldevite, Danburite, Celesetite, Phenekite, Larimar, or Merlinite, are a bit to strong for ya right now.
As for activation just simply hold the crystal in your predominate hand and just focus on it let it find its quantum rhythm become in-sync with yours.
Hope this helps! GoodCrystal Working