Other than as explained, about the improper preservation of the coins, there is another factor contributing to the numismatic devaluation of a coin: their use in jewelry and clothing accessories. 

Coin jewelry offers you unique pieces handcrafted from real coins, including the silver three halfpence. It was used to decorate distinguished soldiers in ancient Egypt. This pieces, whether it be solid coin jewelry or cut coin jewelry, makes an unique gift or fashion accessory that can be passed down from generation to generation.

But in the hobby of coin collection, to the real numismatic researcher or collector in general, the practice of this Art cause an irreversible collateral damage, as many rare pieces of value have been "victims" losing with this all its numismatic value, becoming just a ornamental piece of metal.

Today's craftsmen or silversmiths continue to create coin jewelry pendants, ear rings, cuff links, belt buckles, brooches, also hand painted or enameled coins, and as a demonstration I posted examples of those, some quite curious indeed, as follows in the upcoming section.

Rings made using coins has probably been around since the first minting of coins itself. Wearing such rings goes back farther than diamonds. In ancient times it was a status symbol, proving wealth and power.
Today it lends a certain mystique, a romance that stems from coins as a link to the past. Whether you're looking to "preserve a collectible coin" in an interesting way or just want to create jewelry art, coin rings are an interesting fashion statement.

Δ  This coin ring made of a 1½ pence dated 1841, was create using simple band fashioning and soldering techniques. The band of the ring is stamped Sterling and fits size 7. [1]

A brooch, sometimes spelled "broach", is a decorative jewelry item designed to be attached to garments. It is usually made of metal, often silver, even silver coins, including 1½ pence coins but sometimes bronze or some other material.

Δ  This brooch made of 1½ pences dated 1839, 1841 & 1862, being the last two semi-keys within the series, perhaps was used solely as ornament or sometimes serve a practical function as a fastening.

This is an excellent example of a common practice in the times among emancipated blacks & inhabitants of the West Indies in general of perforate or make a hole in the coins, appears to be used as a way of fastening it to clothing or a string to prevent its owner from losing it, due to its tiny size. Unfortunately many 1½ pence coins, key and/or semi-key dates have been completely damaged and greatly devalued as a result.

Δ  Perforated 1½ pence coins, from right to left, key dates 1837, 1840 and semi-key date 1862 all, embedded in a cotton string as perhaps did the inhabitants of the West Indies in the past to keep the coins, because of its small size, to become "loose change".

A black culture legend tells of how miniature silver coins found use as decorative buttons within the emancipated population of Jamaica and from other islands of the Caribbean, since apart from sea shells as raw material, the three halfpence was worth ¼ Real, so that this way of acquiring silver is about the cheapest for the silver craft production by the poor inhabitants. I could not find any reference to it, but yet I recently bought through the internet, a pair of 1½ pence coins with two holes each, thus I can not say that in this case the holes were made in the past or present times or have been used for this purpose at all.

Δ  From right to left, 1½ pence dated 1835 [Obverse], a button made of seashell [in a comparative manner] and 1½ pence dated 1834 [Reverse]. Both doubled holed William IV 1½ pence coins, sewn into the fabric beneath them, like perhaps, could have been used as decorative silver buttons among poor people in the West Indies.

Clothe studs are small, usually metal objects used to fasten the front of pleated or stiff-front shirts in lieu of buttons. They were first used around the middle of the nineteenth century, when shirt fronts became too stiff to close with buttons, and of course the manufacturers could not miss the tiny 1½ pence, playing a little role because of its smallness in the fashion of the Victorian era. The manufactures indiscriminately used 1½ pence coins from any year or monarch. Clothe studs do not stop being curious and also pieces of history of everyday life in England of the period.

Δ  These silver studs were manufactured by George Loveridge & Co. [1871-1919] based in Spencer Street, Birmingham, U.K. The hallmarks used are marked and described by arrows as follow:

1 — From right to left, letter F for year 1880, anchor for city of Birmingham, lion for sterling alloy [92.5% silver, 7.5% copper] & female head for Victoria.

2 — Initials G·L&Cº within pellet, the mark registered in November 1871 and used by the company until 1885.

They also manufactured other items as brooches, cigarette cases, fob medals, napkin rings, sovereign cases, etc.

A cufflink [also cuff link or cuff-link] is a decorative fastener worn by men or women to fasten the two sides of the cuff on a dress shirt or blouse. The name was born around 1715. Simple, paste-glass buttons had given way to pairs of two, decoratively painted or jeweled studs, connected by ornate gold links. They were small enough to fit through the button hole like a button would.

Δ  This simplest design known as "French cuff-links", even they vary widely,  consists of a short doubled post connecting two disc-shaped parts, in this case two 1½ pence coins of the common date 1843.