I'm going to avoid doing too many 3D printed projects because not everyone has access to a 3D printer. The openscad script is down below. I used natural/transparent PLA.
Main openSCAD website here:-
https://www.openscad.org/
To find the slow colour change RGB LEDs:-
https://www.ebay.com/sch/i.html?_from=R40&_nkw=100pcs+5mm+diffused+led+rgb+slow&_sacat=0&_sop=15
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
Copy and paste the script below into openscad to make a crystal.
//Big Clive 21/Jan/2020 LED quartz
difference(){
union(){
difference(){
union(){
//six sub crystals
rotate([45, 0, 0])
cylinder(h =80, d1 = 30,d2 = 20,$fn=6);
rotate([45, 0, 0])
translate([0,0,80])
cylinder(h =10, d1 = 20,d2 = 0,$fn=6);

rotate([45, 0, 60])
cylinder(h =80, d1 = 30,d2 = 20,$fn=6);
rotate([45, 0, 60])
translate([0,0,80])
cylinder(h =10, d1 = 20,d2 = 0,$fn=6);

rotate([45, 0, 120])
cylinder(h =80, d1 = 30,d2 = 20,$fn=6);
rotate([45, 0, 120])
translate([0,0,80])
cylinder(h =10, d1 = 20,d2 = 0,$fn=6);

rotate([45, 0, 180])
cylinder(h =80, d1 = 30,d2 = 20,$fn=6);
rotate([45, 0, 180])
translate([0,0,80])
cylinder(h =10, d1 = 20,d2 = 0,$fn=6);
rotate([45, 0, 240])
cylinder(h =80, d1 = 30,d2 = 20,$fn=6);
rotate([45, 0, 240])
translate([0,0,80])
cylinder(h =10, d1 = 20,d2 = 0,$fn=6);
rotate([45, 0, 300])
cylinder(h =80, d1 = 30,d2 = 20,$fn=6);
rotate([45, 0, 300])
translate([0,0,80])
cylinder(h =10, d1 = 20,d2 = 0,$fn=6);

//main central crystal
translate([0, 0, 0])
cylinder(h =100, d1 = 50,d2 = 20,$fn=6);
//main crystal tip
translate([0, 0, 100])
cylinder(h =10,d1=20,d2=0,$fn=6);

}
//remove central crystal core
translate([0, 0, -1])
cylinder(h =101.1, d1 = 48,d2 = 18,$fn=6);
//remove centre crystal tip
translate([0, 0, 100])
cylinder(h =9,d1=18,d2=0,$fn=6);
//six sub crystal core removal
rotate([45, 0, 0])
translate([0,0,0])
cylinder(h =80.1, d1 = 28,d2 = 18,$fn=6);
rotate([45, 0, 0])
translate([0,0,80])
cylinder(h =9, d1 = 18,d2 = 0,$fn=6);

rotate([45, 0, 60])
translate([0,0,0])
cylinder(h =80.1, d1 = 28,d2 = 18,$fn=6);
rotate([45, 0, 60])
translate([0,0,80])
cylinder(h =9, d1 = 18,d2 = 0,$fn=6);
rotate([45, 0, 120])
translate([0,0,0])
cylinder(h =80.1, d1 = 28,d2 = 18,$fn=6);
rotate([45, 0, 120])
translate([0,0,80])
cylinder(h =9, d1 = 18,d2 = 0,$fn=6);
rotate([45, 0, 180])
translate([0,0,0])
cylinder(h =80.1, d1 = 28,d2 = 18,$fn=6);
rotate([45, 0, 180])
translate([0,0,80])
cylinder(h =9, d1 = 18,d2 = 0,$fn=6);
rotate([45, 0, 240])
translate([0,0,0])
cylinder(h =80.1, d1 = 28,d2 = 18,$fn=6);
rotate([45, 0, 240])
translate([0,0,80])
cylinder(h =9, d1 = 18,d2 = 0,$fn=6);
rotate([45, 0, 300])
translate([0,0,0])
cylinder(h =80.1, d1 = 28,d2 = 18,$fn=6);
rotate([45, 0, 300])
translate([0,0,80])
cylinder(h =9, d1 = 18,d2 = 0,$fn=6);
}
//Second solid additions
//Add base cone
translate([0,0,3])
cylinder(h =45, d1 = 100,d2 = 7,$fn=6);
//led plinths
rotate([45, 0, 0])
translate([0,0,30])
cylinder(h =5.5, d1 = 20,d2 = 8,$fn=20);

rotate([45, 0, 60])
translate([0,0,30])
cylinder(h =5.5, d1 = 20,d2 = 8,$fn=20);

rotate([45, 0, 120])
translate([0,0,30])
cylinder(h =5.5, d1 = 20,d2 = 8,$fn=20);

rotate([45, 0, 180])
translate([0,0,30])
cylinder(h =5.5, d1 = 20,d2 = 8,$fn=20);

rotate([45, 0, 240])
translate([0,0,30])
cylinder(h =5.5, d1 = 20,d2 = 8,$fn=20);
rotate([45, 0, 300])
translate([0,0,30])
cylinder(h =5.5, d1 = 20,d2 = 8,$fn=20);
//cable entry
translate([0,-35,10])
rotate([45, 0, 0])
sphere (d=10,$fn=20);

}
//Second removals
//Inner base area
translate([0,0,2])
cylinder(h =45, d1 = 100,d2 = 6,$fn=6);
//base removal cube
translate([-50,-50,-47])
cube ([100,100,50]);
//LED hole removal
rotate([45, 0, 0])
translate([0,0,26])
cylinder(h =10,d1=5,d2=5,$fn=20);
rotate([45, 0, 60])
translate([0,0,26])
cylinder(h =10,d1=5,d2=5,$fn=20);
rotate([45, 0, 120])
translate([0,0,26])
cylinder(h =10,d1=5,d2=5,$fn=20);
rotate([45, 0, 180])
translate([0,0,26])
cylinder(h =10,d1=5,d2=5,$fn=20);
rotate([45, 0, 240])
translate([0,0,26])
cylinder(h =10,d1=5,d2=5,$fn=20);
rotate([45, 0, 300])
translate([0,0,26])
cylinder(h =10,d1=5,d2=5,$fn=20);
//main pillar LED hole
translate([0,0,40])
cylinder(h =10,d1=5,d2=5,$fn=20);
//cable entry
translate([0,-35,10])
rotate([45,0,0])
cylinder(h =20, d1 = 4,d2 = 4,$fn=20);
}