Ive been wondering this for a while and foind some info but much of it was to high level of science words for me to understand.

Sorry if this been covered I skimmed through this thread but didn't see what I was looking for at first glance.

So what is it about say Heptane that grows larger and more dense crystals as opposed to Naptha which grows crystals that are so soft they crumble when touched?

Which NPS makes the hardest crystal structures when evaped slowly over a few weeks? I have 2g of dmt dissolved in 100ml of hot Heptane in a martini glass with a cd over it to slow the evaporation.

heptane is a single compound, a seven-carbon molecule.
naptha is a slew of molecules, various straight-chained hydrocarbons and cyclic hydrocarbons, each having varying degrees of van der waals interactions. basically, with naphtha, you pull a variety of compounds, and you use heptane to induce crystal homogeneity, because it is a single-compound solvent, not a solution of various compounds.
naphtha can be used to re-x too, but the crystal resolution won't be the same, because the lattice may have [higher-boiling than heptane] solvents trapped in it

So would there be (or is there) a more selective single compound solvent that would create a denser structure/lattice than heptane? Or is heptane the boss?

My line of thought is that temperature, surface area of SCS solvent, type of evap dish and even pressure can all play roles in formation, along with seeding and type of seed used (shard, mini xtal etc).

Messing with (and varying) temps whilst doing evap stage is easy enough, just not sure what can be done about the pressure aspect.

Does your seed crystal have to be dmt or could I use sea salt? I have some sea salt that is nice and flat. Or even table salt tine little cubes. I wonder if i could use it to seed.

I use a good looking (the best looking, most uniform) small xtal from an initial pull, freeze precip followed by final evap, then clean & re-x.

So far it has not got me a single growth (had one large cluster) in my first three goes and I still mainly get small fields.

Have a new dish to try sometime soon and am going to add variable temps (cooling period slowed) whilst also slowing the evap rate by limiting airflow and surface area interaction.

Something tells me slow and steady wins the race

How saturated or not is your solvent? Say in 100ml Heptane how much dmt will you dissolve?

I think one problem Im having is way too much dmt in the solvent hence crashing out all over the place.

Bearing in mind the heptane is heated and the spice is liquified in the (also heated) carrier dish it is kind of hard to say..

I heat 200ml of heptane via hot water bath getting to about 75-80c or so and then draw up about 30 ml at a time and (carefully) add to the melted spice which is also sat in a hot water bath to maintain its temps while combining the spice (957mg) and solvent. Then I use a glass stirrer to (carefully) mix it up a bit.

I reckon I would be lucky if I use 100ml of the heptane, more likely 60ml.. I will endeavor to get more accurate numbers on future attempts.

On your line of thinking, mine was kind of opposite. Who's to know eh (if someone does by all means step in and shine light on subject matter). I was thinking that if the solution was supersaturated whilst heated this would force a tighter grid/lattice and thus facilitate a larger initial structural formation.

I reckon I will follow this line of thinking and slow down the initial temperature drop while limiting airflow to the surface layer for a longer overall evap time.

I agree a super saturated solvent would be best but my mistake was container shape. The funnel shaped glass causes all the atoms to collect in a big massive cluster preventing the appealing look of individual crystal shapes.

I think I'm going to rapidly evap what I have and start over this time in a flat pyrex square baking tray. Then the crystals wont form all on top of each other. That and a more diluted solvent in the funnel shaped glass so it makes a neat clean cluster.

the best crystal formation I have had was from a hot bath on acrb in naptha (my hot water runs very hot ~140* F)
I pulled it very hot to such a degree any air flow seemed to carry off stream.
it was placed in a sealed jar overnight and in the morning I had 2 large crystals that looked like miniature crystal formations from plant krypton, just slightly yellow not green.

is there an advantage to having big crystals besides aesthetics and bragging rights?

Thats rad wish you had pics. Onbly problem with that is that they are so soft in Naptha and just crumble when touched. With heptane they are pretty hard and can be kept in tact.

I tried taking pics with my phone but this one doesn't have macro mode so they were very poor.

but yes they fell to pieces with the slightest touch.

You have just uncovered the very motivation that moves me hahaha