Mining in Sunshine Islands requires three Farm Tools: a Hammer, Hoe and Watering Can. The Watering Can is used to melt Lava in order to clear spaces AND obtain a rather popular gift item in the form of Gelatin. This is a new option in Sunshine Islands.
As in Island of Happiness and some of the other Harvest Moon games, you can descend to lower floors either via stairs or a Pitfall.
A different Gem may be found on each floor on the first 9 Floors. Note that oddly, you may find a different correspondence on your first visit to the Mine but after that, it should be as follows:
Floors B1 through B9:
B8: Sand Rose
When you reach the 10th Floor:
Dum=Da-Da-DAA! You’ve reached the 10th floor of the mine for the first time! Hm? Who am I? Can’t tell you yet. See ya!
(If you have raised Mystic Islands and met the Harvest Goddess by throwing an acceptable offering into the Pool there, the Harvest Goddess will show herself and make an announcement of similar sort in the Mine whenever you reach a new ‘goal’ in terms of reaching a lower floor of the mine.)
Note that Stone Tablets can be found first on the 50th Floor using a Hoe, and on every 25th Floor after that. Only one Stone Tablet can be found on any allocated Floor. After shipping the first Stone Tablet to complete the entry in your Shipping List, stash them in your Rucksack to gain Mining Points daily from each.
Floor B10: Adamantite
11th through 24th Floors: All Gems apart from Diamond, Pink Diamond and Alexandrite
25th Floor: Orichalcum
26th through 49th Floors: Copper, Silver, Gold
Floor B50t: Mythic Stone and, using your Hoe, Stone Tablet
51st through 74th Floors: All Gems (including Diamonds) and All Ores apart from Mythic Stone, including Mystrile, Adamantite and Orichalcum
Floor B75th: Stone Tablet in floor (using Hoe), but nothing in Rocks
Note that you will find neither stairs nor pitfalls on the 75th Floor unless you have raised your Mining Degree at least to Level 5.
76th to 99th Floors: Copper, Silver, Gold, Mystrile
Floor B100: Nothing apart from Stone Tablet , obtained by using a Hoe
101st through 124th Floors: All Gems apart from Pink Diamond and Alexandrite
Floor B125: Alexandrite and by using a Hoe, a Stone Tablet
B126 through B149 Floors: All Gems apart from Pink Diamond and Alexandrite
Floor B150: Diamond and Pink Diamond
B151 through B174 Floors: All Gems apart from Pink Diamond and Alexandrite
B175: Nothing apart from the Stone Tablet you can find with your Hoe
B176 through B199 Floors: All Gems apart from Pink Diamond and Alexandrite
Floor B200: Nothing apart from the Stone Tablet your can find with your Hoe
B201 through B224: All Gems apart from Pink Diamond and Alexandrite
Floor B225: Adamantite and Orichalcum and, with a Hoe, a Stone Tablet
B226 through B249: All Gems apart from Pink Diamond and Alexandrite
B250: All Gems and All Ores and, by using a Hoe, a Stone Tablet
B251 through B254 Floors: All Gems and All Ores
B255: Wonderful from the Harvest Goddess and, by using your Hoe, 1-2 Stone Tablets
Your worst enemy in the Mine does not consist of Pitfalls but your own Energy limits. By carrying as many Provisions as possible and ALWAYS using a Recovery Item before your Stamina decreases below the halfway point, you will avoid passing out.
Lava is an impediment that can conceal a stairway but you can find Gelatin in any piece of Lava after using Water on it three times. Gelatin is an item that is quite well-regarded as a Gift by more than one Eligible Girl.
If you study the Mining List above, you will see that the best Floors to explore extensively in the early stages of mining are:
Floor 10: Find as much Adamantite as possible to use in creating Makers
Floor 25: Find as much Orichalcum as possible to use in creating Accessories
Floor 50: Find as many Mythic Stones as possible to ship for income
Floors 51 through 74: These are the earliest Floors that hold most of the Gems as well as most of the Ores. The only Gems you cannot find here are the very rare Pink Diamond and Alexandrite. The only Ore you will be unable to find is Mythic Stone.
My own strategy usually is to save whenever I reach a new Floor, then use a Pitfall to fall lower until I am within one or two floors of Floor 25 and Floor 50. I make certain to reach Floor 25 to collect Orichalcum, always needed, and then to reach Floor 50 to collect Mythic Stone, certainly needed for income in the first couple of years. You can find from 5 to 7 pieces of each of these special items on their designated Floors. I never have found more than 7, however.
From Floors 51 through 74, you will find your greatest number of items, both in the form of Ores and Gems. There usually is at least one piece of Orichalcum as well as one piece of Adamantite on EACH of these Floors. It therefore makes no sense to allow yourself to fall through a Pitfall unless the Pitfall takes you only one floor lower, as you then will run the risk of skipping some of these Floors.
As previously stated, it is best to save your game as soon as you arrive on any new Floor, unless you have arrived via Pitfall and lost too much Energy in the process. The amount of Energy you lose when you fall is based on the number of Floors that you travel in your fall. One or two floors therefore is to be preferred, even if it is less tedious to fall through all the Floors that hold little of benefit.
An important consideration in Mining in Sunshine Islands is increasing your skill and Mining Points through experience. Collecting even Junk Ore will add to your Mining Degree Points. You will find that the lowest Floor to which you are able to descend in the Mine is determined by your Mining Degree Level. It therefore makes little sense to push your way to the 75th Floor when your Mining experience is too low to permit you to descend any further. Whenever your Mining experience is too low, NEITHER STAIRS NOR PITFALLS WILL APPEAR NO MATTER HOW MANY TIMES YOU RELOAD!
Spending a lot of time exploring each of the Floors between Level 50 and Level 75 probably is the best way to increasing your Mining Degree total and obtain the largest amount of income. Further benefits are Orichalcum and Adamantite totals, which will allow you to order vital Accessories and the Makers that are used to process Ranch Products and Grains.
Using Wonderfuls in the Mine
Some of the Wonderfuls will have no power in the Mine but Green, Orange and Purple Wonderfuls in your Hoe and Hammer can prove very helpful. Knowing Charlie’s schedule can allow you to trade Wonderfuls from tool to tool, setting Yellow, Green and Purple in the Hamer and Hoe for the duration of any Mining expedition, then taking them back to Charlie for dispersal and use in different Tools.
Inside the Mine, an Orange Wonderful set into your Hammer will allow you to find more Gems and Ores in the Rocks you smash and, when set in your Hoe, will allow you to find more Black Herbs and Coins in the ground. The number of potential Stone Tablets found on any allocated floor will not change. In fact, as the Watering Can is used to find Gelatin in Lava, setting an Orange Wonderful in it will increase the amount of Gelatin you can find.
The Orange Wonderfuls, however, are less vital than a Green Wonderful in this context. Green Wonderfuls decrease the amount of Stamina required for each use of the Tool into which they are set. Stamina always is a valuable commodity inside the Mine. When you are farming, the best place for your Green Wonderfuls to be set probably is your Watering Can but whenever you plan an expedition to the Mine, you may wish to load your Hammer and Hoe with them as well.
The Purple Wonderfuls are the least important as they simply add 2G to the value of items that are obtained using the Tool in which they are set. This is of minor significance compared to the other Wonderfuls.
Alexandrite and Red Magic Flowers
Alexandrite is a valuable item in its own right but it becomes doubly so when used in a Recipe to create the rare Red Magic Flower. Although you can find Red Magic Flower on Sprout Island randomly during the Autumn Season, you can make it in your Kitchen using the rather more common Blue Magic Flower and Alexandrite. To obtain any Recipe, you must give an ingredient to a specific Chef. In this case, you must give Blue Magic Flower to Haila at the Café.
Mining Degree Points
Although you cannot see the total number of points that you have earned in any Degree Category, it is useful to know how many can be earned by any given action or achievement.
The values are as follows:
Use your Hoe, Hammer or Watering Can: 1 point
Descend to another Floor using stairs or Pitfall: 1 point
Obtain any Gem or Ore: 2 points
Ship any Gem or Ore: 2 points
Obtain a new variety of Gem or Ore: 15 points
Participate in the Mining Contest: 100 points
Win 1st Place in the Mining Contest: 1000 points (and a Wonderful as 1st Prize)
Win 2nd Place in the Mining Contest: 700 points (and 3 Wonderful Pieces)
Win 3rd Place in the Mining Contest: 500 points (and 2 Wonderful Pieces)
As you can see, every piece of Junk Ore that you obtain is worth as much as any rare Gem or Ore in terms of your Mining Points. Shipping Junk Ore will give you the same number of points as shipping any rare and expensive item, even if it will not yield as much income!
As previously indicated, the lowest Floor that you can access at any given time in the Mine is determined by your Mining Degree point total. The correspondences are:
For 0 through 500 Points: Floor B10
For 501 through 2000 Points: Floor B25
For 2001 through 5000 Points: Floor B50
For 5001 through 10000 Points: Floor B75
For 10001 through 15000 Points: Floor B100
For 15001 through 20000 Points: Floor B150
For 20001 through 25000 Points: Floor B200
For 25001 through 30000 Points: Floor B250
With 30001 Points, the Mine is yours to command.
This information is included in my Sunshine Islands General Guide but for those who prefer to access this site, this post should be fairly helpful in terms of exploring the Mine on Volcano Island. Note that, in many respects, the correspondences between Floors in IoH and Sunshine Islands are identical.