Wiki has a good list of kinds of economic capital.
Capital – Wikipedia The main point presented is that capital is any asset useful for production. I should add to the wiki list that military capital is useful for producing war, peace and political capital. Christian capital is useful for producing eternal life with the Lord God.
I tend to regard anything of value as capital, since any material or intellectual property may be useful for production of other goods or ideas.
Consider invention of new ideas; pre-existing ideas combined together can produce a new synthetic idea(s). That is comparable to arithmetic where with a three and a two once can produce a five.
Humans exist embedded in a thermodynamic physical field of being in which they are self-aware and aware of the field and characteristics of it objectively. If they were unchanging and static beings the concept of production might not be so important; capital is consistent with thermodynamic change or artificial production that supports human life and its proprietary interests.
Natural capital such as comprise forests and the services they produce in supporting human life, oceans, rivers, clouds, the sun etc all may be regarded as natural capital beneficial to human existence. Ecological economics is a field that values natural capital and seeks to sustain or increase it so far as possible.
Social and political capital exist useful for production in marketing and political goals respectively. The late President Ronald Reagan had much social capital before he began building political capital, for example.
Scientific capital can reap innumerable production benefits. Even the Chinese lunar probe that discovered a gel like substance of unusual color on the dark side of the moon (possible ET scat), may be useful for something someday (coprolite research dump for exopologists). China’s lunar rover discovers ‘gel-like’ substance in crater on moon
Large corporations often have technical and intellectual as well as financial capital that allows quick production of material objects from new ideas they can invent, purchase or redistribute unto themselves from others in sundry ways.
An interesting example of capital is the dirt (regolith) of the moon. Apparently it can yield Helium 3 useful for fusion reactors (or not because there are scientific questions about that) and more immediately, lunar materials could be used to produce a sun screen to reflect light when the mirroring surface (600,000 square kilometers) are launched from the moon inexpensively (compared to Earth) to the Lagrange Point 1. Mirroring surface at L1 facing the sun could screen out 1 or 2% of the sunlight reaching the Earth and cool it down a little. That might be a practical dampener of some of the global warming problem. A moon base would be required to build the sun screen, and fortunately President Trump is trying to fund a moon base (although the global warming problem is not perhaps interesting to him). The moon dirt and other minerals have real value for production.
Monetary capital compounded with investment produces more monetary capital. The 1% have so much monetary capital as well as other kinds that it dwarfs the capital of the rest of society (at least that of the bottom half). The monetary and financial capital of the richest is so deep that it is like a gravity well such as the sun that brings all of the objects of the solar system to orbit around it and eventually gobble them up as would a black hole.