There's a lot of misconception about whether moldavite is from outer space, and when I start distinguishing tektites from meteorites- I get shocked looks that there are rocks similar to moldavite all over the rest of the planet. We also get a call at the shop every week from someone who “found a meteorite” and they get mad at us when we advise them they did not.

So, let's dig deep into the subject of meteorites and tektites, but before we do… let's back it up, to before rocks even enter our atmosphere.

Comets are small icy dirt balls, about the size of a small town. However when they heat up, form orbiting close to the sun, they spew gases and dust- leaving a streak millions of miles long.

A noteworthy comet passes by the earth approximately every 5 years.

Asteroids are rocky objects that orbits the Sun. Asteroids can become very large, to about the size of a small planet- but are not planets because they lack atmosphere. If the rocky body is under a meter in size we call it a meteoroid.

Meteor showers occur as the earth passes through trails of comets, or encounters debris from asteroid collisions, etc. The small bodies of matter enter the Earth's atmosphere, becoming incandescent as they burn up through friction. The streak of light, is what we call a shooting star.

Meteorites are the debris (large or small) lucky enough to survive their passage through the atmosphere of a planet or moon without entirely burning up. 

Tektites are formed during the extreme conditions caused by the hyper velocity impact of a crater forming meteorite. As the impact event occurs, terrestrial sediment and rock become molten and vaporized, ejecting up into the atmosphere in gravel sized chunks. The glassy bodies cool, landing hundreds to thousands of kilometers away from the original impact site.

The fundamental distinction between tektites and meteorites is that meteorites originate from outer space, where as tektites originate from terrestrial (Earth) material. 

Pseudo Tektites, despite having similar appearances to impact event tektites, were formed during powerful volcanic eruption. When magma was spewn into the sky, it solidified and fell back down to earth as obsidian (volcanic glass).

Marekanite, also known as Apache tears, are small round balls of obsidian formed within perlite. perlite forms by various means, but distinctively as flows, beds or masses. It is a hydrated form of volcanic glass that, due to niche conditions sometimes doesn't homogeneously hydrate, leaving areas of volcanic glass inside to form as black glassy balls.

Meteorite TektitePseudo Tektite
Stony Iron Pallasite - Sericho, Kenya Moldavite - Czech Republic Saffordite - Safford, Arizona, USA
Iron - Bendege, Bahia, Brazil Libyan Desert Glass - Libya Agni Manitite (Pearl of Fire) - Indonesia
Stony Iron - Bondoc, Luzon, Philippines Irgizite - Kazakhstan Colombianite - Columbia
Iron - Campo del Cielo, Argentine
Iron - Sikhoti-Alin, Russia

Note: This table by no means expresses all the locations and varieties that exist. Consider it grossly incomplete, but accurate with what it represents.