Gold or Silver in bulk before coining, or valued by weight. (from Oxford Languages dictionary)

The gold standard is fixed monetary regime under which the government's currency is fixed and may be freely converted into gold. It can also refer to a freely competitive monetary system in which gold or bank receipts for gold act as a principal medium of exchange; or to a standard of international trade, wherein some or all countries fix their exchange rate based on the relative gold parity values between individual currencies.

A gold certificate, issued as U.S. currency equivalents until 1934, proves ownership of a specific amount of gold.

1. of or relating to the study or collection of coins, tokens, and paper money. 2: of or relating to currency : monetary (from merriam-webster.com) 

A savings account with tax advantages that individuals can open to save and invest in long term 

The "Ask" price is what a precious metals dealer has set for a bar or coin, also known as the selling price.

The "Bid" is how much a dealer is willing to pay to purchase said metals. This could be new purchase or buyback of coins or bars from an investor. Thus, this is the buyback price. 

The Premium is the difference between the spot price of the metals and the retail sale price. This could include any premiums for minting, overhead, bid price, and profit.

The Melt Value is the value of the precious metal that could be extracted from a coin or jewelry if it were to be melted down. As an example, if you had a 1 oz gold coin and the melt value is $20, then the value of the coin is $20. 

The "spot price" is the price a precious metal is sold or bought in the market for immediate payment and delivery. The spot price is determined by the forward month's futures contract with the most volume. 

A self-directed individual retirement account (SDIRA) is a type of individual retirement account (IRA) that can hold various alternative investments normally prohibited from regular IRAs. Although a custodian or trustee administers the account, it's directly managed by the account holder, which is why it's called self-directed. Can be a traditional or Roth SDIRA.

For Investors: coins have a face value but are valued based on the weight of the precious metal. Sold by gold and silver dealers, local coin shops, and online bullion sellers.

For Investors or Collectors: a U.S. Minted Proof Coin can be purchased through the U.S. Mint or your local dealer. The proof is the finest quality of coin produced. The term "proof" refers to the coin's finish. Proof blanks are specially treated, hand-polished, and cleaned to ensure high-quality strikes. The blanks are then fed into presses fitted with specially polished dies and struck at least twice. The coins are then carefully packaged to showcase and preserve their exceptional finish. When sold originally, these coins have Certificates of Authenticity and encased in a protective capsule. 

For Investors or Collectors: Are hand-loaded into the coining press and struck on specially burnished blanks, yet have a soft, matt-like finish appearance. These coins: Are made like circulating coins (which are used every day as money), but with a special process that produces a brilliant finish. Come with an official Certificate of Authenticity.

For Investors or Collectors: Are produced for circulations, but those sold directly by the United States Mint are never released to the Federal Reserve Bank. These coins: Are typically offered by the Mint in rolls, bags, or boxes, which do not include Certificates of Authenticity.