Factors that make Zakaat compulsory

Zakaat on property

Q:

  1. Is Zakat due on the current market value of the land or the original value at which it was bought given that the land is still in my possesion? Also the intention of buying this land is to build a house for personal use.
  2. In order to avoid Riba (interest) to buy a house without mortgage, I am intending to buy land(s) such that after few years I will buy a house for my own personal use after selling 1 or more lands. Is Zakat still due on this land(s)? If yes then on principal amount or current market value?

Zakaat on graded Mandela coins

Q: I have a few graded Mandela R5 coins (year 2000 and 2008) that I have acquired. They are legal tender, but because of their demand and rarity, I bought them for a few thousand rands. I purchased them with an investment intention. How do I pay zakaat on them?  The coins have no gold or silver in them.