Small crystals. :D
sugar crystals are just small sugar pieces that combine into sugar cubes
It is likely that the mineral formed from molten lava on the Earth's surface. This is because it would have cooled very rapidly, so forming the small crystals.
Paper sheet having small undissolved alum crystals
Dimonds
It's not that only alum makes big crystals.. There are so many compounds that can make big crystals. Even Sodium Hydroxide makes very good and big crystals. For crystals you need a uniform arrangement of atoms in space. For big crystals all you need is patience. The slower is the crystallization process the bigger crystals are formed. What industries do is called seeding. They make a good concentrated solution of the compound whose crystals are needed and then they put a crystal of the same compound in the solution. The new crystals form and attach to the crystal making quick and big crystals.
porphyry
Such rocks are called porphyritic.
It's an igneous porphyry.
It stinks, it has hairs on it. And it has small white crystals called keif on it.
Intrusive rock normally has visible crystals. Extrusive igneous rock has small crystals. A black extrusive igneous rock with small crystals could be basalt.
Andesite has small crystals because it cools quickly.
It depends on the type of igneous rock. Intrusive igneous rocks such as granite have large crystals, extrusive igneous rocks may have small crystals as in basalt or no crystals as in pumice.
diorite crystals are large and andesite crystals are small
Ah, a classic. It is porphyritic. The classic example is granite.
The rock cools so rapidly from magma that crystals barely have time to form.
Since basalt is extrusive it cools quickly and forms small crystals.
it depends on the heat, if it cool very quick then it has small crystals but if it cool very slowly than it is bigger the slower the cooling period the bigger the crystals